Sapinda relationships are prohibited under hindu marriage law. A sapinda is someone who is:
- within or has a common ancestor relative within three generations above you on your mother’s side of the family
- within or has a common ancestor relative within five generations above you on your father’s side of the family.
A sapinda can be someone from your father’s side or mother’s side hence, you are not eligible for a hindu marriage if you marry someone who is a Sapinda.
Jail time up to one month or a fine up to Rs. 1000 or both is the punishment but there are exaceptions. In some cases, if the custom or usage allows marriages between sapindas.1