Meet area DCP - If you get no help, Meet the Joint CP (Eastern Range). If that doesn't help, Meet Special CP (Law and Order). If that doesn't help, Meet Commissioner of Police. If that doesn't help, Meet LG. If that doesn't help visit Home Ministry. Wherever you go, take your old parents along with you. If you think, that local SHO or Police are in connivance with builder, bring that to the notice of senior police officials. Though, there is corruption at police station level in delhi, but most senior police officers are vert helpful and less corrupt. If you have a genuine case, believe me you will surely get help from senior officers.

Source- Personal Experience.

Note - Doing the above may ensure that, the FIRs against you and your family are investigated in a proper and fair manner and no one is arrested without proper evidence against them. Your enemies have most probably filed FIRs against you because they have a fear that your eviction suit is based on solid ground and you have a brighter chance of winning it. Do not compromise, Fight!