play online

what up nlsc is online play still available for the game

No, online support ended a long, long time ago. You can still play via IP to IP on PC.

so what all do u need to have to do that what information connects them (pc to pc)

You need your IP address, an opponent's IP address, and to be online at the same time. One of you will enter the other person's IP to issue a challenge, they'll accept, and then you play.

Do u have to play with default roster or both players gotta have the same rosters

I believe you can play with custom rosters, as long as you're both using the same roster and have it loaded.