I am from Maharashtra state board. I have started my board preparation from now. I can score 75%+ in my HSC???
Good luck!:)

Remember, the early you prepartion is the more time you shall have for Competitive exams Like JEE, AIEEE, NATA , MHTCET.
By the moment, Class 12 exam starts you should have completed 50% sylkabus by mid year.
So you have ample time for practice and revision.
You can also solve previous year Board exam papers to gauge how much youbscore and how much more prepartion you require.