Should I start studying now ????

So just completed 10th boards , joined pw arjuna which starts on 7th April . I have around 20 days , everyone around me started studying for jee and i am feeling that i am lagging behind. I was thinking of studying like 5hr for now and when the classes begins i will give my best then . But till then like 5hrs and some hobbies.
Can anyone who has passed this stage advice me ? Should i go full fledge from now only or study for only like 5-6 hrs till 7th ?