Brother Yash Dev I am preparing for jeemain. I need to join in robotics in any govt Colleges If possible. I am SC CANDIDATE. Now let explain me clearly. I got 86 percentile in January. Not only yash dev brother anybody can give me the suggestion. Please don't regret my question.

Hello.
First we need to calculate your Approximate all India rank for getting a probable idea about your chances ,ok so it will be calculated using the formula given below:
Approximate Rank= (100-your total score)*869010/100.
Here 869010 is the number of candidate appeared for the January session of exam, now your approximate rank with 86 percentile would be: 121661 it is your approximate common rank it will definitely change according to the fluctuation because it depends upon the number of candidate appeared for the exam, difficulty level of the exam, total seats available.
With your approximate  rank  your chances are very less to get a government college for robotics even for robotics branch you need to have a good rank near about under 10,000 -20,000 (excluding category relaxation) , and your percentile must be 95 + now it depends upon your category so you may consider some relaxation also, there are various government/private colleges which offers robotics branch in BTech you can see  through the below link:
https://engineering.careers360.com/colleges/list-of-be-btech-in-automation-and-robotics-colleges-in-india
Now I would suggest you to appear for the July session of exam and improve your percentile and rank if you have registered for it then it's ok and if you haven't registered  so you will have to wait for the next time because application window has been closed now.
for more predictions you can refer the link provided you below and can use the college predictor tool:

Best of luck.

Siri, though there are approximately 15 Engineering Colleges across India that have B.Tech in Robotics Engineering, they are all Private Institutions. Dr. MGR Educational Research Institute is the only Government College with this course. Now with the only Govt. Institution offering this course, the cut offs will be usually high. With 86 percentile, your All India Rank is approximately 74,000. Even with SC reservation, it might be tad difficult. Agreed that cut offs change every year depending on various factors but any percentile less than 95 will be difficult for a seat here if your goal is a Government Institution.