How can I score 75% and above in Class 12th with 3 months of preparation?

why dreaming less.. you can score around 95% with 3 months study in class 12th..
i flunked in pre-boards in maths, got around 60% in physics and barely passed in chemistry…then scored 96% in boards…
so do not panic, start studying, religiously…
set up a time table, and try to stick to it ( i know how difficult it)
for a month or so, renounce social media, though you can glance through quora..
and do not forget to enjoy the last, precious moments of your school life, you cherish them throughout your life
all the very best…