Since these books are copyright protected, these are not available in any of the websites for free of cost. you can try the ink

https://studentnews.in/pdf-verbal-non-verbal-reasoning-rs-aggarwal-free-download/

or you can try olx website to get the book free of cost

Yes , I know the software through which you can download n number of ebooks of various fields like school reference books(like RS aggarwal and all) , also IIT Jee Books , technologies related books .. It Basically contains all types of books and from all departments books..I am sharing the link of that software..(PLEASE NOTE -- This is not the promotional Answer, i am telling my own experience to this software..)

link-- https://b-ok.cc/ and https://z-lib.org/

I hope it will help you .. Thank You