Hello Jyotsna

According to academic consil admission into cw category will be done on the priority basis given as follows

1. Widows/wards of defence personnel killed in action

2. wards of serving personnel and ex serviceman disabled in action

3. Widows and wards of defence personnel who died in peace time with death attributed to military services

4. Widows and wards of defence personnel who disabled in peace time with death attributed to military services

5. wards of Ex serviceman and serving personnel incluiding personnel of police forces who are in reciept of gallantary awards. 

The cw certificate should be issued from competent authorities like

1. Secretary kendriya sainik board

2. Secretary Rajya sainik board

3. 11st class stipendiary magistrate etc.

Hope this helps.