Should I mention about my brother sponsoring me for UK? Can I have another person bearing my expenses other than me?
The Immigration Rules V4.2(e) states “The applicant must have sufficient funds to cover all reasonable costs in relation to their visit without working or accessing public funds. This includes the cost of the return or onward journey, any costs relating to dependants, and the cost of planned activities such as private medical treatment.”
Although V4.3 says that a 3rd party can provide funds, maintenance and accommodation, an applicant has a much stronger case if they can show they meet 4.2(e) in their own right. If you don’t need a sponsor, don’t mention one.
If someone is paying some or all of your trip expenses you must state that information in the application and provide evidence that the person is willing and able to fulfil the commitment, for example a letter from the 3rd party, their bank statements and payslips.