Hi Aspirant

Here you can download all the materials for you.

https://engineering.careers360.com/download/sample-papers

https://engineering.careers360.com/download/ebooks

Apart from this you can buy sample papers by Arihant ,MT&G publications .They are also good and will be helpful to you.There is question bank named "38 years of Question IITJEE" which you can get in book store or some online stores like amazone ,flipkart whatever suits you.

Hope this would be helpful

All the best.