Non Refund of Booking amount

We had booked a flat promoted by V Raheja in Andheri.. under soft launch.. The money paid is substantial.30% of the total flat amount. There is a Letter of Option to purchase which was signed by both the parties.. This letter provides an opportunity to exit if the builder does not get the required approvals to commence with the property. The builder has not got the requisite approvals., We have raised a demand but the builder is not willing to oblige. Further we have got to hear from the broker we engaged that the builder has become bankrupt servicing the interest on loan taken. There has been further development on this.. There is some other agreement between V Raheja and Omkar developers to resolve some clearances from AAI.. (Airport Authority).. We get to hear that the Omkar has obtained the marketing rights. Further Omkar has publicly started sourcing the flats in the same project with different configurations. What options are available to complain.. The total cost of property is `1.88 CR.. and 30% has been paid.