Yes you are definitely eligible to give both the exams , according to infomation bulltin of neet 2018 which states that " The upper age limit for candidates seeking admission in MBBS/BDS seats shall be 25 years as on the date of examination with a relaxation of 5 years for candidates belonging to SC/ST/OBC category and persons entitled for reservation under the Rights of Persons with Disabilities Act, 2016 "

You should start preparing , give the exams and register yourself to the colleges.

You can also refer neet official infomation bulletin  for more info (https://cbseneet.nic.in/cbseneet/Welcome.aspx)

OR this website (https://medicine.careers360.com/articles/neet-eligibility-criteria)

I hope the information will help you .

All the best !!