Hi aspirant,
You have obtained 87.92 percentile in JEE Main and belong to General category. You can refer to the previous year closing rank NIT Srinagar to see if you can get admission there based on your percentile or rather rank. https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-cutoff-for-nit-srinagar/amp
In order to predict your other college and branch options, you can use the JEE Main college predictor tool by clicking on the following link: https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer
Now as far as your category change is concerned, I would like to say that your category cannot be changed at the time of counselling. You should have entered it correctly at the time lf registeration itself or needed to correct it while the correction window was opened. So during counselling it cannot be changed.
Wish you all the best.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile