Wow! You've set a very high bar for yourself, which is a good thing.
A score over 310 would essentially rank you somewhere in the top 800 rank holders, which is a very conservative figure. You could do much better rank-wise if things go well.
To score 310+ in JEE Mains, you will have to give up a lot of things. All distractions will have to be eliminated. You should be ready to work every second of every minute of every hour if you want to get such a high score. Some preparation tips have been illustrated in the link below.