IBD Builder defaulted on delivery of flat in Bhopal

IBD builder in Bhopal has defaulted on the delivery of the flats. There are approximately 100 people who booked flats in 4 buildings in the same premise in E8 Extension of Arera Colony.. The builder's contention is that the property came under NGT ruling as there is a rivulet that falls within 33mts of the construction area. However 2 buildings of the site do not fall in the 33 mts area and these 2 buildings are 90% complete. Now the builder says that he does not have money to complete these 2 buildings. It has been 6 years since the booking of the flat. Till date, most of us are paying pre-EMI with no hope of resolution of the matter. HDFC bank is a culprit in this in equal measure as it did a pre - check of the property and only then sanctioned loans. It now refuses to entertain any arguments Please help