IIT

You need to score more than 150 in order to get admission in any of the IITs.

It's not possible for you to get admission in any of the IITs with 55 marks as your rank would be more than 25k.

Here is the list of colleges which accept JEE Advanced.
https://www.shiksha.com/b-tech/colleges/b-tech-colleges-accepting-jee-advanced-india

No, the seats in IITs are purely based on merit. They do not encourage management seats.

Hello Siddarth, Yes you can do. There are 3 attempts for JEE Mains and 2 for JEE Advanced and the board exam scores are valid till then. Hence you can appear for the exam and get admission if you crack it with a good score. All the best !

Check this link for the colleges arranged in rank wise:
https://www.shiksha.com/b-tech/articles/2019-mhrd-ranking-of-engineering-colleges-in-india-blogId-15711.

Your marks is average. There is a less possibilities to get good IIT, but you qualified JEE Advanced. So, you don't have to worry, because you definitely to take admission in any good college which provides good package.

You should join a good coaching center. You will find good competition there. To prepare well, you need competition and guidance that will motivate you for your studies.

There are less chances for you to get admission in any of the IITs as your score is quite good, but not sufficient to get into IITs. Use the rank predictor to know your rank and if you are under top 8000, you can get a good IIT with good branch.
https://www.shiksha.com/b-tech/resources/jee-advanced-r

I don't think so, you can get electrical engineering branch in decent IIT at this mark even in OBC NCL category. But, your score is good, and best of luck.