Hi aspirant ,

we cannot tell you that you can  surely score 100 marks in 13 day ( in case you are starting now)  but we can try, firstly choose the two subject in which you are  good  at and you can score well . please don't waste your time on the subject you don't know, because you are  having less time . prefer the weightage of the questions because you are having total 180 questions in maths 60 and chemistry 60 and physics 60 , and prepare according to it. the subject you don't know just learn the  basics to answer the basic questions and also refer the sample question papers.

sample paper link is being provided below

https://engineering.careers360.com/articles/kcet-sample-papers

All the best!