Diploma Holders can apply for direct into second year of B.tech programme. Here are some of the private colleges you can prefer for Lateral Entry takes the admission through its own entrance test:

Manipal Institute of Technology

Chitkara University

Thapar University

If you want to know about any particular college then let me know, I will help you with the procedure.

Good Luck!

Hii.
After your diploma you have to write a exam conducted by a your state boards like example KCET by Karnataka and MHCET by Maharashtra
So check out and clear exam depends on your rank you'll get college while there are few private colleges have there exam like VITEEE by VIT UNIVERSITY  you can get by those
Hope this helps