Hello, hope you are doing well, you jee mains is only the entrance to get into the jee advanced. You might not have done well in jee mains due to many reasons like no proper preparation, tension and lack of confidence. But believe me, for advanced you need to be through with the concepts not with the formulas and important topics. Jee Mains is like direct answers but in advanced you need to put pen and paper and solve it.

Stay positive and prepare well, you can qualify advanced:)

Keep  Smiling:)

Wish you good luck!:)