how do i give sucker punch to Crimgan or Druddigon?

Unfortunately, you will need a father in the same egg groups (dragon or monster) as druddigon with sucker punch, none of which occur in pokemon black and white naturally.

If you really want sucker punch on crimigan, you'll need to bring one of the following pokemon from a previous generation, that has had sucker punch MOVE TUTORED onto it: Nidoran (male) Nidorino Nidoking Seviper

Or if that is not possible, you have one other option: Ekans and Arbok

Ekans and arbok, must too have this move bred into them, but their parent pool is a little more flexible, so you can breed the move into ekans with a father with sucker punch from its egg groups and then breed it into druddigon.

The fathers that can breed it into ekans are: ratatta, raticate, diglett, dugtrio, sentret, furret, poochyena, mightyena, Mawile, Spinda, Kecleon, Absol, Glameow, Purrloin, Liepard

(plus pokemon from gen IV that have had it tutored onto them or bred into them, but we don't want to go into that :S )

Sorry that it's a kind of lengthy process, good luck :) Remember, the father needs to be any of the listed pokemon with sucker punch and the mother needs to be a druddigon.

Happy breeding ;)