Incase a student applies under ECA category as well as Open General category for UG Admissions, will rejection under ECA category mean rejection under Open General category as well? As it is possible that All certificates submitted under ECA are rejected for one or the other reason.
You can select only one category at the time of admission or application into the ug courses. In case the reserved seats get exhausted, you can them claim the open/ general/ unreserved category's seats because these seats are not reserved for anyone and are allocated strictly on the basis of merit. If any discrepancy is found in any of your documents, this will jeopardize your admission.