In the Mahabharata Kaushika gotra is mentioned and kashyapa gotra might have mentioned. Are the two gotras same?
In Hindu society, Gotra broadly refers to people who are descendants in an unbroken male lineage from a common male ancestor or patrilineage.
Kashyapa was one of the eight original gotras (clans) of the Brahmins, being derived from Kashyapa, the name of a rishi (hermit) whom they believed to have heard the Veda.
On other hand, Brahmins belonging to the Vishvamitra Gotra/Kaushika Gotra consider Brahmarshi Vishvamitra as their ancestor. As Brahmarshi Vishvamitra was also known as Rishi 'Kaushika'[He is the son of the king Kusha.]
So Kashyapa gotra is NOT the same as Kaushika gotra.