Thats a beautiful schedule that you have set up for yourself and it is also very disciplined. If you stick to this plan with minimal or no distractions, there should be no reason as to why you cannot score 600 and above. May be you can just follow the below guidelines for a maximum utilisation of your study period.

There is something called PATS Model in Psychology which the University ofTorontohas published some time back.

Picking the Best Environment for you to study: This is important because you should feel secure and comfortable but not too comfortable where you might fall asleep.

Always reducing the visual distractions: Make sure you have nothing within your vicinity to distract you. Like keep your phone a side. Or sit away from the TV, Windows where you can see people.

Try to Eliminate Noise around you: If you are someone who can concentrate with music, make sure it is light music and nothing to distract you. It should increase your ability to concentrate and not distract you. If there is any noise that might distract you, use ear plugs or a fan. Trust me, if am being distracted by noise, I switch on the fan and it works.

Self talk to control Internal Distractions: When you are noticing that the mind is drifting aside, stop what you are upto and keep a checkmark on a piece of paper along with the time. Keep a track of these checkmarks and the timings. Talk to yourself that you understand you are being distracted but you also have to study. If it keeps bothering you, write down what is it that is bothering you and promise yourself that you will come back and look into that. Now that has been parked in the notebook, get back to studying.