hi,

see if you are dedicated, hard working and if your concepts are clear for mathematics, physics and chemistry, you can surely achieve a good rank.

1 month is more than enough to study. just follow some basic rules,

wake up early and revise the lessons,

make short notes to remember before the days of exams.

make a routine and practice daily as much as possible questions.

Lakshya being in the top 100 all over India is not a very easy thing to do. It will all come down to how good you have prepared over the last one month and how well your fundamental are. As only one month is left , all you can do is revise everything but don't go to hard as people do get worked but in the last month and lose their focus.