There i sno upper limit for total attempgs in NEET UG exam from 2018 onwards and thre attempt maximum rule hasbeen scrapped by superme court of India. 

Age is to be within 25years for unreserved category and 30 for reserved category. Minimum age should be 17yrs.

https://medicine.careers360.com/articles/neet-number-of-attempts-and-age-limit