I am a 1st year B.Tech student of a private engineering college under AKTU. How can I get admission in a better college in 2nd year?

I think it will be very tough or may be impossible. Still, if there is any chance, try to get more than 9 pointers or 85% in the first year.

You can apply for the college of your choice through lateral entry, but you need to qualify the entrance exam and the PI to pursue B.tech in the college of your choice.