Castling and Capturing

Can the white king castle here and capture the knight?

I was wondering if you could legally castle and take the knight with your rook.

That's an interesting question but as I understand the rules of castling one can not do it if there is any piece between the king and the rook. I would think that this would apply to an enemy piece as well.

You can't capture a piece when castling. Castling is a strictly non combative move only allowed when all pieces, yours and opponents, are cleared between the rook and king and your king never walks into check when castling.

Thankyou for the information.

[UNNECESSARY POST]

Hey what if the Knight is on c1, will the King be able to capture then?

Castling would be illegal. As mentioned previously, no pieces can be between your king and rook.