The goal of SRE program is to develope to demonstrate reusable tech like ,hypersonic reentry and NC&G tech, recovery for 2nd stage of RLV-TSTO.
Isro tested SRE-1 way back 2007.They further conduct SRE-2 .
DMRJ stands for Dual mode ramjet,means ramjet & scramjet engine in same powerpack.IIRC...