Hey yogesh! 

Here are some books you can refer too - 

Iinear algebra by s kumaresan

Introduction to real analysis by bartle and shelbert

An introduction to probability and statistics by rohatgi

Statistical inference by casella 

You could isi msat study material in Kindle app as well.

Here are some apps you could check out - 

Udemy 

LinkedIn learning

Khan academy

Study blue

Wish you all the best!