i cleared 10th and i have 20% Mark's can i get admission for b tech.

For BTech course one needs to complete 10+2 with Physics, Chemistry & Mathematics as compulsory subjects. After 10th you can't take admission in BTech.

Now if you wish to join a college for Engineering, then I would recommend you to go for the course of Diploma in engineering. For this course, you have to qualify the polytechnic entrance examination which is to be organized by your State Technical Board.

After your Diploma in Engineering you can appear for the Lateral entry examination which can provide you admission to the BTech. Now with 20% marks, you may not be eligible for the Diploma course. A minimum of 50% is required atleast for the entrance.

For the state wise polytechnic entrance you can consider the link below:

https://engineering.careers360.com/articles/polytechnic

I hope this helps. Wish you a great eve!