S. 4 : Charge of income-tax-Joint venture of Central Government and State Government-Rail corporation-Metro rail project-Separate legal entity-Income derived from corporation from business activities could not be said to be income of Karnataka State Government under article 289-Capital or revenue receipts-Sales tax referred-Matter remanded to the Assessing Officer-Interest on fixed deposits-Interest earned from fixed deposits of surplus funds after commencement is taxable though it was received for expansion of the project. [Companies Act, 1956, art. 12, 289]