I was in the same situation as yours couple of years back and was distracted in my first year of 11th standard due to lots of reasons and then tried my best to bounce back in the following next year. It's better to start now as it is rightly said Better LATE THAN NEVER. 10 Months are not less, you can do wonders in that. Firstly, Please quit Fb, whatsapp etc and all these social media.

Avoid wasting unnecessary time like watching 2–3 movies in a month is nothing to be entertained. Don’t give much importance to friendship too. This stage only studies matter nothing else.

Tips in general:-

1. Have a timetable. Be specific in what you’re gonna to study in that period. For eg at 8th July 2016 from 12 pm to 3 pm I am going to solve Electrostats from DC Pandey(book) from question no’s 1 to 100. And mind you you must complete your targets on time. Don’t try to have much backlogs.
2. Allot one or two days in a fortnight to clear backlogs, I mean keep them empty. (By backlogs I meant the targets you failed to achieve)
3. If you like you can listen to some soft music
4. Have confidence that you can clear jee with top 10 ranks. I kept my target as rank 1. Never doubt your abilities. Motivate yourself.
5. Have some sort of motivation . Like after clearing JEE you’ll be on top of world. Everybody embraces you, You’ll become the king. No body doubts your veiws. No problem in hospitals and banks for queue. For me, I have been watching movies and playing sports since then, 24x7 Fb, gaming and having parties once in two days is sort of common. You’re facing worse to prepare for the best.
6. Watch inspiring vedios when you’re low. This vedio inspires you to get into IIT
7. Think that you’re already an IITian( don’t be overconfident tough) and talk to parents like that.You’ll realize what are you working so hard for.
8. You may take some sort of breaks if you want.

Regarding, the subject part

1. For physics:- Have good concepts. IIT asks entirely on concepts. If you have them strong you may even score full marks. Have good theory portion. Solve tough questions and apply concepts on them. Mind you IIT does not ask too typical concepts or some sort of Hi-fi ones. They’ll stick to the basics and you must also too.
2. For Maths:- Practice as much as you can, from different books or worksheets. Nothing beats practice here. Avoid using calculator(Tough I used it a lot)
3. For Chemistry:- Develop your interest in chemistry at the earliest. Chemistry is the subject which will surely give you an entry into IIT. I tough didn’t like chemistry as much as maths and physics, I scored more than 90 in JEE 2016 paper in it. Maths and physics were around 40’s 50’s mark. So please concentrate on it, its really important subject.
4. Physical chemistry:- focus on concepts as well as practice.
5. Organic:- Be thorough on concepts. Do not attempt to mug it. Focus on mechanism. Try as many as question you could preferably from Himanshu Pandey book.
6. Inorganic:- I think you know it better than me. Just mug it up 10–12 times before jee. No other solution till now.
7. Please do solve previous IIT questions well before JEE,like from the daynext to JEE main.[Seriously important point]

At the end, give equal importance to all 3 of them. Each one is important. I was strong in all 3 like all other IITians who got rank under 2k. Any queries you may ask me. Hope so I would get chance to counsel you about taking which branch in which college. All the best and be happy!

My bestest of wishes for you brother. Thank-you.