Itr form for employee benefit trust exempt u/s.10(23aaa)

Facts:

1. Trust is created for the benefits of employee by a company
2. Trust provides medical assisstance to the employee and its dependents for the cost of medical treatment
3. Trust has obtained registration under section 10(23AAA) of the Income Tax Act
4. The Trust has received initial corpus fund from the Company and further receives a monthly contributions from all it members (employees of the company who has opted to become the member)

Questions:

1. Which form of ITR should be used for filing the returns of the trust
2. How and where do we need to disclose the income exempt u/s. 10 (23AAA) -(Income = contributiuon minus the benefit settlement made by trust during the year)

Please help me out with the answers along with supporting justifications/judicial pronouncements (if any)