Next 2021 practice kit published by the edugorilla publications would be really helpful to for nest exam.

The book is available in both offline and online and the best way to purchase online is at Amazon in which the book is available for rupees 225.

This book contains also then practice mock test for NEST exam.

And also contains the previous year papers of nest exam.

You can also refer to these books for their nest exam.

For higher algebra you can prepare hall and knight book and for biology you can refer the NCERT book.