My whole internet dies to the point that i cant even access my router when i get a DCC send from a person, who is most likely on a very high speed, he sends over 200 kb/s to me and when it reachs that mark my whole net dies. Can I restrict mirc to how fast i want my DCC Gets?

no you cant.

I suggest you get the firmware on your router updated, its liekly the point of failure.