Obtain consent of society for sale of car parking slots 

If the car parking is show separately and registered in sale deed then you can sale same to never through registered sale deed and can purchase his covered parking .

Open parking comes under common area, cannot be sold. If you have paid for it, you have been duped. If there is no objection from other members, you can sell.

At least, with flat sale, parking will also transfer to buyer for use.

1. Open /Stilt /Podium /Basement Parking spaces are all classified as "common open spaces" & Free of FSI, under the Regional Town Planning Act and CANNOT be "legally" Sold or Purchased or Registered or Leased. Parking spaces can be allotted (most of the times by illegally collecting money, which is a criminal offence).

2. IF the Society resolutions permits such exchange on records, THEN it is possible, otherwise both parking slot users can execute an MOU for such exchange of parking spaces, without any monetary considerations. Such MOU will have only "persuasive power", but is legally not enforceable.

Certainly you can

Yes you can do so as it's legal to sell car parking in rera. You can better execute a exchange deed in the same. But if the open parking is society parking then you can't sell it. Only if you have paid to builder then you can sell it

Ans:- On what basis can the builder register open car parking space in your name. Its considered as common area and hence the builder has in fact cheated and duped you if you have paid any consideration for that parking plot. 

Dear Sir,

As you said, stilt and open parking area would be considered as Common area. Therefore, the builder has no right to impose car parking charges as confirmed by the Supreme Court. ... Hence, many builder will allocate this area and the same point would be mentioned in the Sale Deed as like flat covered car parking.

Way back, on 31st August 2010, the Supreme Court of India ruled that a builder/ developer/ promoter (of flats/ group housing) cannot sell open or stilt parking area (meaning uncovered or covered parking space) once the owners' society is formed, as the said space becomes a part of “common areas and facilities” 

If you have a registered sale deed in respect of parking space separately then you can sell it separately. You first ascertain the facts and then proceed as per law. The car parking space are common areas which belong to the association hence you may clarify the details from association before venturing into any such deals.

Yes if the parking is allotted to you then you can exchange the parking slot with exchange deed with other resident.

1. What does the sale deed say about this?

2. Car Parking cannot be sold as it is a part of common area, but it can be exchanged.

to sell car parking society permission required.