Services Selection Board (SSB) comprises of senior officers from armed forces of India. Generally aspirants search for remote data rather than brushing up their present knowledge. First of all you prepare on your bio-data. Your present residence and permanent residence places, their prominence, your schooling, your family members and their fields are basic in preparing of NDA SSB interview.
Current Happenings around you
The next best thing in preparation is know what is happening around you. The native state current happenings, the happenings at national level, the happenings at international level are the points to observe and brush up. Not confine to only political events around you but cover the events with social responsibility and awareness.
Do n’t concentrate on learning new things at this stage. Just remember the basic concepts of your studies(spc course). Generally the Board members ask questions not to test your memory but your understanding on those concepts. Be clear in answering questions. Be brief in responding. If board members expect more, then only be elaborative on the topic asked.
Last but not least
As we already pointed out it is not only test of knowledge but also test of personal qualities, be confident and clear with positive attitude.