Dear Student,

Yes, you can do your M. Tech in Computer science after, B. Tech in Electrical. But to do so, you have to give GATE exam in CS and score .But it is very tough. Though M.Tech CS has some preparatory courses in the first sem, this is not so easy. And if you want to pursue M.Tech CSE from top IIT's then you have to get a very good rank. So, you have to work very hard.

Hope this helps.