Hello Aspirant,

See if you want to attempt free mock or previous year paper of Biology for NEET 2021 then you can do so because NTA has already provided the facility of free mock test and previous year papers and sample papers for NEET 2021 can be downloaded from the links given below :-

NTA mock test :- https://nta.ac.in/Quiz/Home/Login?PaperID=175

https://medicine.careers360.com/articles/neet-question-paper

https://medicine.careers360.com/articles/neet-sample-paper

For NEET, there are some standard mock tests but are not offered for free but it will definitely worth you more than you pay for it because all the mock tests were prepared by the subject and examination experts according to the pattern of examination and difficulty level of examination. You can get complete solution for NEET from the link given below and it also includes various mock tests along with many other features :-

https://learn.careers360.com/medical/neet-preparation-material/

I hope this information helps you.

Good Luck!!