1) it is necessary to peruse your agreement with builder
2) was there a clause in the contract that in event of breach of contract you could encash the bank guarantee of builder?
3) if builder has illegally sold your portion of flats you should have filed suit to direct builder to vacate portion of your share of flats and for damages for loss suffered by you
4) since the case is already sub judice you will have to wait for suit filed by you to be disposed of
5) it is necessary to peruse reliefs claimed by you in the suit
6) you must have also filed police complaint of cheating , criminal breach of trust against builder
7) you cna amend your plaint in civil suit and claim damages for loss suffered by you
8) no need to file separate complaint before consumer forum