Previous year JEE Main qualifying marks for general category was 100. It is expected that it will be around 95-110 this year.
You have chances in JEE Advanced.

If you want to take admission in IIT you have to get serious as there is huge competition. You should be motivated and determined to crack your exam.

You can follow below points for your preparation

1- You should refer NCERT books for your preparation. Make sure your basics are clear. Don't use much reference books. You can use good recommended books for your preparation.

2- You can use previous year papers to understand the exam pattern and level of questions.

3- You can solve as many as MCQs for your practice and to build up speed and accuracy. You should solve short-answer questions, subjective-type problems and questions based on assertion reasoning to develop deep understanding of the subject.

4-Important topics you should cover for JEE Advanced are:

    Physics: Mechanics and Electrodynamics are the two most important topics but one should also devote time to Heat, Thermodynamics, Optics and Modern Physics.

    Chemistry: General principles of Organic Chemistry are easy to understand. Numericals of Physical Chemistry are scoring. Inorganic Chemistry has many facts and figures and requires constant revision.

    Mathematics: Master inter-relationship between various topics. Coordinate Geometry and Vectors can help one to solve problems related to complex numbers. Permutation and Combinations help you to solve problems of Probability. Trigonometry and Calculus again help one to solve all types of problems.

All the Best!!