You have to play this game very smartly. On same day you have to file case in the RERA and Consumer Forum. At the same time take the principal amount back in the form of DD or NEFT transfer. And don't sign any terms and conditions documents with builder for refund amount.

File complaint against builder before consumer forum and seek orders to direct builder to refund your money with interest 

2) also claim litigation costs and compensation for mental torture undergone by you 

Its better you go for consumer forum if you want interest and compensation. You can opt for rera also

If you take the refund then you cannot file complaint Before consumer forum against builder.

And if you file case before consumer forum or civil court Then you may have to wait for another two to three years if compromise is not done by you. 

You can take back your booking amount with protest or objection first.

After that you can file a complaint against the builder before the consumer forum seeking interest as well as compensation. 

If you refuse to accept the refund of booking amount then you may have to wait for years to get back even that amount. 

issue a legal notice through an advocate to builder and file Complaint before Dist Consumer Forum and seek order to refund Amount along with compensation for mental agony. 

1. IF you take back the Principal amount, THEN legally it would amount to that you have forgone the other claims (Interest /losses /compensation for physical & mental trauma), unless you have signed any agreement /contract /undertaking with the builder for the delay /whatever ....

2. File a grievance petition before the local consumer court, with all available & relevant documentary evidences, for the negligence & harassment caused by builder and claim your principal amount alongwith Interest /losses /compensation for physical & mental trauma.  There are many positive court judgments available on such matters and you too will get sure success.

Yes firstly take the amount then file a complaint before the consumer court seeking interest and compensation for the delay.

Dear Sir,

At the time of taking back your amount you must be very careful that you should not give any undertaking that you do not proceed against the builder in RERA or Consumer Forum. Anyway it is advisable to take back your principal amount and thereafter start litigation.

Real estate development and Regulation Act 2016 do not provide any jurisdiction to real estate regulator in this regard as your project is not approved and registered with RERA Authorities.

Since you paid the amount to the Builder in 2010 it is long time and The RERA was not in existence so you have the option available is file your complaint against the Builder in state consumer disputes redressal Commission because you paid the amount in 2010 calculating the interest @ 24% will give you some additional amount to claim along with legal charges, compensation and the legal expenses. total must go more than 20 lakh rupees which is eligibility to go state consumer dispute redressal Commission to qualify  to avoid filing complaints in district consumer forum  which will take additional time to decide the case and finally builder may go for appeal in state consumer Commission . commission will order the Builder to appear before the court and decide the complaint based on fats and merit.

It's better to first take the full refund and then proceed further with legal action for wrongful retention of money for more than 2 years, breach of trust, causing loss of opportunity and mental hardship, etc.

If you receive back the amount without interest now, later on you cannot proceed against the builder for interest and compensation, if the builder is not willing to pay it now along with your principal amount, then you must first issue a legal notice demanding both these along with your principal amount, since he has already refused to accommodate these, you can file a complaint with the district consumer court and receive back your money with interest and compensation for loss of other investment opportunities. 

Take refund of principal amount from builder 

then sue the builder to recover interest 

after taking amount you can proceed. 

In order to avoid the confusions about filing a consumer case at a later stage towards the interest portion, you may first issue a legal  notice to the builder about refund of amount with interest.

After that accept the booking amount being paid by the builder in full.

Later on file a complaint before the consumer forum for the balance amount (towards interest).

Dont be dejected or discouraged listening to unnecessary rumours, you may try your luck, let the court decide.

See you have right for compensation and interest even after the refund. See if no undertaking or compromise or settlement in writing is done then in that case there is no issue in proceeding with the case.

You can proceed to consumer forum after taking refund of principal amount on ground that you have lost many opportunities during that period due to delay of possession and refund of money. 

You can seek principal amount under protest and then move to consumer court for relief