If a nephew gets gift money in his saving account from the NRE account of his uncle, how much limit of the gift money should be & whether the gift money is taxable for nephew?
Is it required to be documented?
From an India gift-tax point of view, you can receive unlimited funds from close relatives. So if you are getting this from your Father's Brother or Mother's Brother; then it is not taxable.
It is a good idea to document this if the amount is large. It serves as record for future. This can be a simple piece of paper or something that's type on Notarized document.