So thanks for asking this question. I’ll be happy to do his chart analysis. Not only because he is well known and a top producer and also the son of a very eminent producer. But also because of his sexual orientation of being gay. This I say because during the course of my consultations I have analyzed the charts of at least a handful of people who are gay. Talking with them has made me understand them better. I gave a consultation to a lesbian and in the chat she said “Sir please do not hate me because I am a lesbian, this is the way I am born”. I replied to her that “God loves you and who am I to hate you”.
The first time that I came to know of this was in the early 90s. I had gone to visit my wise friend Sharma Ji (now in Chicago). But in those days he used to live in Vasant Kunj, Delhi and once he pointed at a bunch of boys and told me they were “Homos”. I asked him what does that mean and then came to know. Of course, the term is seen as derogatory now.
Now this generation is very well versed with all this but in our times we used to hold the hands of our friends and walk in the park. We were all straight. In Canada I came to know that holding hand with the same sex was regarded as being Gay!

Source – https://en.wikipedia.org/wiki/Karan_Johar
Birth Details
25/5/1972; 1200 Hours; Mumbai
Lagna Chart

ASC Leo 02-08-11
3rd house of Libra has Moon 08-44-08
5th house of Sagittarius has Jupiter [R] 13-29-13(Lord)
6th house of Capricorn has Rahu [R] 05-27-45
9th house of Aries has Mercury 28-19-38
10th house of Taurus has Sun 10-40-27 (Enemy)and Saturn 15-43-14
11thhouse of Gemini has Mars 14-39-52 (Enemy)and Venus 11-12-06
12th house of Cancer has Ketu [R] 05-27-45
Dasha
MER from 10/ 8/22 till 10/ 8/39
- MER – VEN till 4/11/28
Analysis
So this is a very lucky person because he was born with a silver spoon in his mouth. However, his relationship with his mother and father is not the best. I would say it is not bad, but it is not the best either.
This is the first time I am seeing the chart of a gay person with such good planetary placements with regard to romance and/or domestic life. I say “such good” because there are some minor problems. His 5th house has Jupiter, which is retrograde. A retrograde Jupiter is never considered good for children and can indicate legal problems. But Jupiter is also the lord of the house, which means fatherhood is indicated — in his case, fatherhood through surrogacy.
He has an alternate lifestyle. Because he is wealthy, he can come out openly about his sexual preference. Wealthy celebrities are also increasingly coming out publicly and saying that they are gay or depressed. But the common person in India cannot always come out because of the fear of discrimination. That is the double standard we face right now.
The other thing is that his Venus is very good. It is in the 11th house, but Mars is an enemy there again. This means his partner will be from a high-flying social family or a prominent social background, either in Mumbai or overseas, but there will be trouble in his union(s).
There is an indication of an alternate sexual preference, also because Mars is an enemy of Venus.
As I understand it, homosexuality is legal in India, but same-sex marriage is not legally recognised. So this is the balancing act because India is still a very traditional country.
Coming back to his chart, Karan is an egoistic person, with Leo ascendant at two degrees. So that also gives him some traits of Gemini ascendant. Work-wise, he is very egoistic, but he can be a dependable and reliable friend. He likes to enjoy life and have fun. He is flirtatious.
The 3rd house has Moon, which means the auspicious presence of the mother is indicated. He has no other sibling and is the only child. People often say that Kaal Sarpa Dosha (KSD) does not mean anything, but here you can see that between his 6th-house Rahu and 12th-house Ketu, Moon and retrograde Jupiter, the lord, are coming. That is why he has no other sibling; he is the only child. It is not that his parents would not have tried for another child, but they would not have succeeded.
The Moon in the 3rd house also makes him emotionally very strong, although he can have his weak moments too.
Jupiter, the lord, is retrograde in the 5th house. As I said, this is a good placement, though tricky because of KSD. This means he is very wealthy. He may have legal trouble, but because of his wealth, he will be able to take care of those troubles. Difficulty in becoming the father of healthy children is also indicated.
The 6th house has Rahu, which means enemies are present in both his personal and professional life. They may hurt him, and health-wise, he can have sudden issues. He has to be careful about his health and should not take too much stress.
The 9th house has Mercury. This means this person will live and work in luxury, in air-conditioned offices, leading a very sophisticated personal and professional life, where people will generally do as he pleases or as he orders. He will be a nice person to talk to, with a very refined and sophisticated personality. He is literally born with a silver spoon in his mouth, and he is continuing the successful profession of his father.
The 10th house is also very powerful. It has Saturn and the Sun, which are enemies. This means that he is not particularly bold in the sense that he will come out fighting with everybody who disagrees with him. Instead, he will operate behind the scenes and handle matters politically. In that way, he is very tactful. He knows how to manipulate situations.
His relationship with his father was also up and down — not bad, but inconsistent. Saturn in this house means that authority and money through the family, as well as through his own hard work and profession, are indicated. He is a very wealthy person and is very authoritative in Mumbai circles. Nobody can touch him there.
Sometimes he can make bad professional decisions, so he has to have good managers.
The 11th house has Mars and Venus, with Mars being an enemy of Venus. This means he has belonged to a high-profile family since birth. Sometimes, when he is irritated, he can become angry and upset, and that can impact his romantic life.
The 12th house has Ketu. This again means he has to be careful about his health. His 11th house also ensures that he will travel all over the world and in luxury.
At the same time, this is a person who can sometimes be argumentative, more so if he does not like something. He will argue his way through it. This is part of his personality. He can put up a good argument without necessarily getting angry.
He is fifty-plus, but right now he is going through his extremely auspicious 9th-house Mercury Mahadasha, which continues until 2039. So, for the next 13 years, provided he does the remedies for the planets marked in red and yellow, things will be excellent for him.
From 2039 onwards, he enters his 12th-house Ketu Mahadasha, when the next generation will take over the business.