Help admission in btech

Dear Creation
Yes, you can join B.Tech program after completing polytechnic in the diploma of engineering. You can take admission in B.Tech through two examinations. One is through lateral entry entrance examination and other is engineering entrance examination.

If you take admission through lateral entry examination after polytechnic then you will get admission directly into second year of engineering. The Lateral entry examination is state level examination. According to your rank, you will be able to choose the college from your state at the time of counselling. In most of the engineering colleges there is reserved seat for lateral entry. But in IITs, there is no lateral entry seat.
In Andhra Pradesh, it's common entrance test. Every state is having different names..

You can also take admission in B.Tech through engineering entrance examination. For this you have to appear in engineering entrance examination like JEE or any other state level engineering entrance examination. But through this examination you will be able to take admission in 1st year of B.Tech and might be chances that you can get admission in IITs or NITs but for that you need to prepare.
But I think it's better for you to try first for lateral entry examination in this way you will be able to save your one year. If you dont get admission in good college through lateral entry, then only you may try to take admission through engineering entrance examination
All the best.