Whether interest earned out of foreign contributions be shown as fresh foreign contribution receipt during that year or not? Can the fee paid by the foreign delegates/participants attending/participating in a conference/

Yes. The interest earned out of such deposit should be shown as second/ subsequent foreign contribution receipt in the annual return during the year in which it is earned. Foreign delegates/participants paying "delegate/participation Fees" in foreign currency for participation in a conference/seminar which is utilized for the purpose of meeting the expenditure of hosting the conference/seminar and is not treated as foreign contribution and as such no permission under FCRA is required.