1. Every company like Tseries , sony india has authorised representatives and agents also you can approach company for the rights they can make an agreement on yearly or monthly basis for the revenue generated and can provide you all those songs which are licensed to them.
2. She you can download it from official website that is other thing and free circulation by you is different things by providing software for free.they might generate revenue by advertisement or promote there other software so if the software is licensed the permission is required.
There are lot of website circulating these free software but it is illegal if no permission though the company donot have that kind of track resources to track and file litigation but they can do.
Like recently microsoft sent many website like this notice for circulating free word or the un authorised version.
See if you are using a substantial part from any movie or vedio or song for trimimg for.making new vedio the license is required if you provide that song if user upload and you provide facility to only trim than that is not the issue.
They won't mention there permission license in terms and condition if they don't have license the original owner can take steps against them.
See there are license website like saavaan gaana and work on appropriate authorizations.