B.Tech public relations

Yes, you can pursue BTech with even 50% or more in PCM but IIT and NIT may not be possible if you're a general candidate but there are many private universities and GFTIs which offer B.Tech with this criteria even with decent placement. Some are like SRM University, Lovely professional University, Amity University etc.

Try to give entrance exams like JEE or state entrance exams, they can give you an edge at the time of taking admission in GFTIs (government funded technical institutions).

I'm from NIT Durgapur, currently pursuing B.Tech in computer Science department and the reality is placement mainly depends on your skill, college just provide you a platform to sit for placements.

So with college, remember to work on your skills.