Reasoning

In all other pairs, second is the name of the dynasty founded by the first.

All except Colt are names of places where animals stay.

All except Circle are figures made up of straight lines.

All except Banyan are coniferous trees.

All except Billiards are outdoor games.

All except Plastic are biodegradable materials.

All except Chanakya were ancient kings.

All except Deuce are terms associated with cricket.

All except Mathematics are branches of Mathematics.