Increased in built up area to be paid on current market price

I had booked the flat in mid 2010 at the rate of 5800rs. For which possession is still not given. Now builder has merged with some other real estate house to complete the project by 2019 and all the construction and managment responsibilty is of new real estate builder. I have some questions, 1. They have increased the 55sqft in builtup area. For 55sqft they are asking money on current market price i.e. at the rate of 10900 (I am ready to pay the rate of 5800 in which I had booked. Can he ask the current market price for increased area.) 2. Previously we had one car park for 2.5 bhk(which i had commited and buyed at rs 4lacs) and now he's saying it is complusary to give 2 car parks to 2.5 bhk and above as per mumbai government rule. Now since I had only one car park and second is made compulsary and he is asking the car park money as 7lacs which is current market rate. For some people those who commited in 2010 he is giving extra parking at 4 lacs. 3. When I booked the development charges where 100rs per sqft + 75000 for electricity connection cost. Now after new builder on board he's asking for 250rs per sqft lumpsum amount as development charge. Can he do that?? 4. As compared to previous plan, there were less activity area in the project...Now after the new biilder is onboard he has uncreased extra aminities(yoga lawn,outdoor chess board, pet park etc.) After adding all the cost and whatever would be my aggrement value, he is asking 15% more as a new builder cost without giving reason?? Can he ask such money from me. When I booked I had given only flat allotment letter and payment receipfs. Agreement is not executed yet. He has not given anything in writing just informent all the buyers in the meeting Also when I booked I booked it in 10:90 scheme. But now he is stating rbi has stopped transactions in 10:90 scheme hence no question of coninuing the scheme since banks will not give loan. Hence he's making my payment plan as construction linked plan. Can he do that? This property is in north-eastern suburb of mumbai