Hii Rohit,

Coming to your question around 1.5 lakh candidates appear from all streams ie SA, SB and SX out of   200 to 250  aprrox get selected in kvpy exam 

And this varies every year. For this year the seats are  SA-75    , SB-66      , SX -144

These no of students will  get selected from different streams in kvpy exam.

For more information you can go to the link stated below

https://school.careers360.com/articles/kvpy

Hope this helps you ,

Good luck:)