sir/madam I am pursuing 1st year b tech in Bangalore but studied till intermediate in AP am I eligible to write AP EAMCET in 2020. could u pls say what are the formalities

As you have completed your Intermediate from Andhra Pradesh, you are eligible to write AP EAMCET. There are other criteria also like minimum qualifying marks etc. You can check the eligibility criteria from the link below-

https://engineering.careers360.com/articles/ap-eamcet-eligibility-criteria

But when you qualify AP EAMCET and participate in counselling at the time of document verification you need to provide necessary documents which means that you need to take your certificates from the college where you are studying. In such cases you may have to pay the fee if college demands while leaving to get your certificates which you have submitted in college and transfer certificate from present college.