Hey,
Some b-schools accept family business as work experience and some don't .
It's better that you have work experience in an organisation or registered company.
As many universities see that the work experience is valid or not because many students fake their work experience.
So you should have offer letter, date of joining and date of leaving with you as a proof
Work experience gives you an edge in the admission process.

Hello Aditya,

Yes family business is considered as work experience in all Bschools. Work ex gives you an edge over the ither candidates during admissions and placements. Exposure to work ethics and corporate world is considered to be an advantage and hence work experience is favoured in bschools to a certain extent.

You should have a work experience certificate or pay slips as proof for the number of months/years of experience.

Hope this helps.

All the best!