With a score of 100/300 in JEE Main, you may consider your Percentile to be anywhere between 94-95. With this percentile, we can estimate a percentile between 50-60k, and irrespective of whether you use EWS/Home State Quota, you wont get a good branch or a good NIT at this score/rank. You may get a GFTI under Home State Quota or a Lower Branch at your Home State NIT, but I would advise you to target a CRL atleast above 40k and a corresponding Percentile/EWS Rank, or a score above 130-135/300.

For more information about JEE Main and Preparation Tips do follow the link below

https://engineering.careers360.com/articles/jee-main-preparation-tips