I got 39.6% in pcb aggregate and I am from minority caste and it states I need 40%..Am I eligible to study in Russia if I am..will there be any kind of issue in MCI exam?

Shyam, it is not clear what you mean by Minority. While checking NEET eligibility, the Categorisation is broadly done as General Category, OBC, SC,ST. And the Community you belong to will fall under one of these Categories. And to be eligible for NEET, you should have completed your 12th, passed in all subjects and secure a minimum aggregate of 50% in Physics, Chemistry and Biology. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. Now if you belong to OBC Category, the Category you belong to should be also listed in the Central OBC list. Or else you will be considered as General Category and so you have to secure a minimum aggregate of 50% in Physics, Chemistry and Biology. This 50% is inclusive of the Theory and Practical marks scored in Physics, Chemistry and Biology collectively. You needn't score 50% in Physics, 50% in Chemistry and 50% in Biology separately. You need an aggregate of 50% or 40% depending on your Category as an aggregate in Physics, Chemistry and Biology. And along with Physics, Chemistry and Biology, you should also have studied English as one of the core subjects in your 12th. With 39.6% unfortunately you do not qualify for NEET even if you belong to the Reserved Categories because the minimum required aggregate os 40%. You may have to appear for your Board Exams for improvement again. This is because NEET is also mandatory for studying MBBS abroad. And once you clear this hurdle, get a seat in Russia to study MBBS and you complete MBBS successfully, when you come back to India to appear for FMGE, your 12th  marks are not considered.