Hello,

To be honest you may not qualify JEE Main with 30th percentile unless you belong to pwd category. As you have not mentioned your category it is difficult to answer. But if you belong to general or reserved category you will qualify JEE Main. A safe score is 85 percentile or above to have good chances of qualifying JEE Main. You cannot expect a seat with the percentile that you scored. If you are appearing in JEE Main September session you should perform well and try to score minimum 85 percentile to get seat in a college.

A 30 percentile score in JEE mains, is quite low, amigo, to be really frank about it. You will have to look for some other options such as state level exams or for some other private universities. If there is JEE mains once more, you can give that too. Try to get a better score in it so that you may get some decent colleges.
Good luck!