I've done a D-D transfer in Srinagar(Leh-Srinagar-Mumbai) last year with 1 hour time. - separate tickets/airline. I had hand luggage only and security check in Srinagar was busy and detailed as expected. I still managed to get ~10 minutes in the (very sad) lounge there. It was not possible to get the connecting flight BP in Leh. it was stressful but I took the risk as flight tickets from IXL-BOM were close to 40K last summer and this came up to 12k