How a candidate can be selected in INA after 12th with min 60% in board with maths and physics?

Hi, Hope you are doing well.
Indian Naval Academy Examination is conducted by the UPSC (Union Public Service Commission).

Your age should be between 16.5 to 19.

You should have physics and mathematics as your core subjects. You can even give the exam while you are in your 12th standard.
Medical qualifications are an integral part of the selection procedure. Your eye sight should be according to the range that’s asked by them. Some other medical requirements

• Good hearing ability.
• Absence of nose, throat or ear disease.
• No speech impediment.
• No granular swelling.
• Well formed chest, joints, limbs and toes.
• Absence of Hernia
• 
  and some more which can be found on the website of Indian Navy.
  You can also find the complete information on the website.