I booked a flat with Omaxe Green, and they promised to pay rent if possession was delayed beyond 24 months. Now, they’re refusing to honor this agreement. What legal steps can I take against them to get my rent?

You can file a civil suit in a court of competent jurisdiction against Omaxe Green for breach of contract. You should present evidence of the agreement, including the clause about rent payment for delayed possession. The court can order Omaxe Green to pay you the promised rent, along with any other damages you may have suffered due to the delay.