I have a friend who has been living in his Uncle's rent controlled/stabilized apartment for about four years, his Uncle is 92 years old and pays a ridiculously low rent by NYC standards, the uncle no longer wants anything to do with the apartment, and my friend was wondering if he can somehow get his name on the lease?? Any thoughts? *I know, he wishes his uncle cool.

Ths site should help:
NYC Rent Guidelines Board

There is good news and bad news. He qualifies by having lived in the apt for more than 2 years. However, he doesn't qualify directly as a family member. However, there are aome additional rules for someone who has been a resident. So he needs to check the rules.