I want to know seats available in National Defence Academy and let me know further details of exam?

As per your concern I will let you know information of National Defence Academy and seats criteria, so that you can get idea.

Seat details
The total number of seats offered by UPSC for NDA and Naval Academy is 375. The allocation of seats for each category is given below.

Candidates are advised to see the table below
Army 208
Navy 42
Air Force 70
Total Seats 320
Naval Academy (10+2 Cadet Entry Scheme) 55
Grand Total 375

Eligibility
Nationality
The candidate should either be a
Citizen of India
Subject of Bhutan
Subject of Nepal
A Tibetan Refugee

Physical requirements
The NDA physical requirements are very important for the selection in NDA. The candidates applying for NDA must have the following physical requirements
Height - Minimum height 157.5 cms (162.5 cms for Air Force). The relaxation of height is applicable for the following candidates

For Individuals belonging to hills of North Eastern Regions of India, Garhwal and Kumaon, the minimum acceptable height is 5cms less.

In a case of candidates from Lakshadweep, the minimum acceptable height can be reduced by 2 cms.

Height relaxation up to 2.5 cm can be allowed in the case where Medical Board certifies that the candidate is likely to grow and come up to the required standard.

Physical Conditioning
All the desirous candidates are advised to keep themselves in good physical condition, by following points mentioned below:

Running 2.4 km in 15 minutes
Skipping
Push ups and Sit ups (minimum 20 each)
Chin ups (minimum 8)
Rope Climbing: 3-4 meters

Qualification
For Army Wing of National Defence Academy: Candidates should have passed 10+2 pattern of School Education or equivalent conducted by a state Education Board or University.

For Air Force and Naval Wings (Cadet Entry Scheme): Candidates should have passed 10+2 pattern of School Education or equivalent with Physics and Mathematics as the main subject by a state Education Board or University.

Candidates appearing in Class 11 are not eligible to take the examination.

Candidates appearing in Class 12 or equivalent under the 10+2 pattern of School Education or equivalent can also apply.

Exam pattern
The Exam of NDA 2017 will be held in Pen and Paper mode and in two sessions – morning and afternoon.

The written examination will comprise of two papers – Mathematics and General Ability Test. Each session will be held for 2½ Hours.

The total marks alloted for the written examination is 900 marks.

The Mathematics section will comprise of 120 multiple choice questions while General Ability Test will comprise of total 150 multiple choice questions. The SSB tests/Interview will carry 900 marks.