Maintenance from father in law as husband is mentally unstable

Can a married lady demand and get maintenance for herself and her kids from her father in law who is very well to do because her husband is mentally unstable and cannot work and earn when the marriage was done fraudulently by the groom's family as they hide the fact from bride family that their son is mentally not stable and is undergoing treatment for the same. Both the families are hindus. If yes what is the legal procedures for it as the groom's family is not ready to take any responsibility and unwilling to help her in any kind. Also what rights she has on the property of the groom's family as the ancestors properties is sold by the father in law and they don't want to give her and the kid's any share.