NTA GAT–B, BET Entrance Test online applications 2021. National Testing Agency Inviting Online Applications for Graduate Aptitude Test- Biotechnology (GAT-B)/ Biotechnology Eligibility Test (BET) – 2021 The Graduate Aptitude Test–Biotechnology (GAT–B)/ Biotechnology Eligibility Test (BET) is a National Level Entrance Examination. Duration of Online registration and submission of online Application Form for GAT–B/BET–2021 : 07