I have given my class 12 exam in 2016 but I was fail at that time but as a private candidate I have passed class 12 in 2017. After that I have dropped 1year form 2017 to 2018 for neet. But in neet application form I have put my details of my class 12 not as a private candidate.. I have given the school name as my previous year school name. Will there be any problem in counsiling? 

You don't need to worry. Since you did your class 11 and 12 from a regular school you would not come under private. You will not face any issue. Anyone who has done his +2 from a regular school doesn't come under private candidate category.

So should I fill as appearing in 12 class or passed in 12th class in my Neet form????

You have to mention passed and year is the one you originally passed in

So, I will have to give my last year marks ????

Please go through this question form the FAQsQ. What year of passing should I enter in my NEET application form if I have appeared for improvement exam after Class 12?A. As long as you are appearing in the improvement exam only to get better marks and not because you have failed in any subjects and wish to pass, then enter the original year of passing only. That is if you have already cleared your Class 12 with the necessary passing marks in your first attempt, and that these marks are above the required marks for NEET eligibility, then that should be the year which you should enter in your application form and the Code should be 02 or 03 depending on your Board. However, if you haven’t cleared Class 12 and are appearing again to pass certain subjects in the exam, then you should enter as appearing and choose Code 01 as your qualifying exam code.

Thank you

I belong to obc category but in my school they have put me in general and I have filled my Neet form as obc candidate .will there be any problem??????