Should I buy a franchise or develop my own brand? Why?

If your product/service is different from the competition, then develop yours.

It is difficult to develop own brand but without facing problem, nothing we did.

I can't tell until at least i know what is the competitive industry . 

Branding or company profile is important, people reconize the name and not the person or product first.
Developing your own franchise need patience and time and for that one should lot of money.
We eat McDonald or Pizza wherever we go, but to any other brand we need to see it popularity.
There are some local names within city itself but it take time to be renowned in the region.

There are merits and de-merits in franchising and branding.
The important point here is your objective and the way you getting there.
Simpler way to look at is the strenths, weekness and the company posses.
Some companies are very good at forming franchises but some are not.
The oppertunities, market conventions and the size of the market always matters.
Therefore the best ways is to test the competencies the company posses and move forward.
Inputs from SWOT analysis, Competency mapping against competitors and Diamond theory would be very useful for studing the markets.