Getting an IIT is not that easy and it is very difficult in your case. In order to crack IIT you must score above 200 and so. Also the final merit will be based on both jee mains and advance. It is clear from your query that you have been trying for 2 years and still you want to try and cracj jee. If you have 100% confidence that you will crack the exam and you can get IIT then you try for the 3rd time but it is difficult if you cannot make up. So my suggestion is that with your 2019 score try to enter into the course with the good college and start with youe career. Or if you really want to go for jee 2020 then work hard to get marks 250+ for good IIT. A link is provided ehre you can find out the branch wise cutoff for various IITs which will help you better to choose the institute.

https://engineering.careers360.com/articles/jee-advanced-cutoff