I have get 51 in physics (21theory+ 30 practical), chemistry 51( theory 22+ practical 29), biology 74( theory 46+ practical 28),

Where are you form ....? Assam state board or other state board or CBSE

Dear Aspirant

To
be eligible for NEET, the marks obtained in Physics, Chemistry and Biology
taken together in qualifying examination shall be 40% for SC/ST/OBC
candidates and without any doubt you have enough percentage to be eligible for
NEET. And for government colleges you should secure a very good all india rank.

Hope this helps you.

Hi Priyanka,
You are eligible for neet counselling.  A pass percentage of 40 is required for a sc st candidate to be eligible to apply for neet counselling.  In order to make yourself obtain a seat in a government medical college you must score higher at least above 420 in order to obtain a seat in government medical college through state counselling.  Prepare well and give your best in the examination to increase your chances of obtaining a seat.  Be confident and give your best in the examination.  Have hope and wait for your possibility to obtain a seat.
Hope this helps
All the best