People belonging to a particular gotra may not be of the same caste (as there are many gotras which are part of different castes) in the Hindu social system.
However, there is a notable exception among matrilineal Tulu speakers, for whom the lineages are the same across the castes.
People of the same gotra are generally not allowed to marry.
At weddings, the gotras of the bride and the groom are read aloud to verify that they are not breaking this rule.
A list of major Brahmin gotras according to the Sutras:[1]