Sapinda or not?

Hello,
As per Hindu Marriage Act, all kinds of first-cousin marriage is illegal in India, Same gotra marriage is legal too while it is not in some communities and Marriage between cross-cousin is legal i.e. you marrying your second cousin or third cousin from your mother's side.

The man and woman who wish to get married should not be within the degrees of prohibited relationships, unless the customs or usage, permits such a marriage.

Regards,
Joy Bose

The marriages under same Gotra are forbidden due to the close connection of DNA among a boy and a girl if they belong to the same clan. People who have similar gotra are considered kith and kin and the rational given to avoid same-gotra-weddings is that genetic deformities may arise due to closeness of genes. Modern science also proved this. hence prohibited.