If you're from Bangladesh and currently studying B.Tech in CSE in India, you can appear for the GATE exam in India itself. You don’t need to go back to Bangladesh to write the exam.

Since you're already studying at an Indian institute, you are considered a foreign national studying in India, and you’re allowed to write GATE just like Indian students. You can apply online, choose your exam center in India, and write it here.

Just make sure to have the required documents ready like your valid ID proof, passport or student visa (if asked), and eligibility proof like your college ID or certificate, Everything else in the GATE process remains the same.