Yes, you are eligible for b.tech admission. All you need to do is make a choice between government and private colleges through which you want to complete your b.tech.If you want a seat in Government College, entrance exams are the only way to secure a seat. However, for admission in private colleges, direct admission through management quota is possible apart from entrance exams.B. Tech after the diploma is always a good option, as a combination of core knowledge + practical knowledge. In order to be eligible for b.tech after diploma you should have successfully completed your Diploma in engineering, You must have an aggregate of 45% throughout your diploma course and your minimum age must be 18 years. If you fulfill the mentioned eligibility criteria,  then you can take admission in B.tech through entrance test.