Transfer of pagdi property from uncle to niece

Hello, My wife is now a British citizen and I'm to apply for citizenship in an year and half. My wife's paternal uncle in Mumbai Khar wants to transfer his pagdi one bedroom flat to her as he has no heir. The land is under leasehold under a society. I have few queries based on this, below: 1. Does my wife need to pay transfer fee to landlord under such circumstances. 2. What will be the registration fee for such a transfer? 3. Will a stamp duty need to be paid and what will be the valuation if such a transfer from uncle to niece is being made without any sale being made? 4. What will be tax implications as my wife is British citizen? The landlord had earlier agreed to make the transfer for an amount of inr 50k, according to my uncle. Please advise.