I find 2 possibilities here..
1. Since the time rape came into light kutumb has been alway taunting indira about mandira's marriage.. So indira might request rishi to marry mandira.. (hope mandira refuses)
2. Sameer might show indira the barsati scene pics.. He might blackmail her saying that marry him or he will publish this pics in media.. And to save her sisters bachi-kuchi ijjat she might agree for that too..
What do u feel friends? Do share your views..