1) What is the main role of Token amount? Should it be treated as a confirmation of the sale?
Token amount means an advance amount or part of sale consideration amount given to the vendor by the buyer as an assurance for the transaction. This can be recorded in the sale agreement deed.
A sale agreement deed can be drawn on the agreed terms and conditions between both and get it registered.
2) Does the builder have the right to decline the amount?
If there is a termination clause n the agreement, the builder cannot deny the payment, you should confirm the same and issue a legal notice if he reuses to return the advance amount.