Yes you can give that Mock test again and solve some more sample papers too. Because score below 100 won't even help you apply for various medical courses. The eligibility cutoff to apply in various medical courses was 135/720 marks in 2019. So you need atleast these marks and above to get eligible first.

Here is the link below that you can use to clear your concepts. This has video lectures from experts and also decent noted..

https://medicine.careers360.com/articles/neet-video-lectures

Below are some of the preparations tips and tricks for the same..

https://medicine.careers360.com/articles/neet-preparation-tips

Below are some more sample papers for the NEET exam..

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

Best wishes. Thank you.