Landlord refusing to accept rent and increasing rent what can be done

A tenant since 1966 in mumbai this property was in my father name then after my father passed away was in my mothers name and since 1995 the rent receipts are in my name the landlord is my father brother. Since 2016 he wanted to increase the rent from rs200/-pm to rs500/-pm I agreeded to the same my mother advised me not to do so but i felt it was fair. But my landlord (my uncle) refuse to accept rs500/- per month and now wants rs2000/-pm which I refused. Cause I feel it is unfair had tried to send him rent as rs200/-pm for the year via moneyorder he refused to accept it, this was before we would discuss any thing about increment in the rent. The place in question is used for commercial purpose since 1966. My query is it legal to increase the rent this high secondly where in mumbai can i go and pay the rent if the landlord is refusing to accept it (pls help with the complete address of the place) .If in case u need more details to answer my query please feel free to contact me. Thanks.