Hello aspirant,

The eligibility criteria for entering in Navy is

• The candidate must be an Indian male unmarried person.
• The candidate must be between 16.5 to 19.5 years
• Passing 10+2 from a recognised board with physics as a compulsory subject.

If you are fulfilling these criterias, then you are eligible to give NDA and enter Navy.

To know more about NDA please see this link

https://www.google.com/amp/s/competition.careers360.com/articles/nda-eligibility-criteria/amp

Hope this information helps.