Let’s assume we have 3 branches: A, B, & C and all of them have their own administration.
- Can we install/host it at a central location and all our branches connect to it through internet?
- Can the admin of branch A login to the system and see the details of A only?
- Can the owner of the chain login and see the details of any branch or aggregated reports of all branches?
Gibbon was not actually designed as a multi-school-information system but I don’t see why it couldn’t meet your needs maybe with some compromises here and there. 
- Yep, why not. You will have 3 independent installations, one for each branch.
- No. Make the admin a user of all three installations and he will be able to access data of all branches.
- Yep, why not. Only branch specific reports can be generated. Overall reports can be generated outside of Gibbon e.g. using spreadsheet.
Gibbon was not actually designed as a multi-school-information system but I don't see why it couldn't meet your needs maybe with some compromises here and there. :)
- Yep, why not. You will have 3 independent installations, one for each branch.
- No. Make the admin a user of all three installations and he will be able to access data of all branches.
- Yep, why not. Only branch specific reports can be generated. Overall reports can be generated outside of Gibbon e.g. using spreadsheet.
Thanks a lot for your prompt response!
I will have a look at it and will get back with questions, if any.