In the given circuit, the equivalent resistance between A & B is ( if A has negative potential and B has positive potential)

⇒  -Ve polarity reaches to P side of  D1, then D1 diode is in Reverse bias ⇒ +Ve polarity reaches to P side of  D2, Then D2 diode is in forward bias    R2,R3   are in series    R23=R2+R3=6+8=14Ω R23,R4    are in parallel   R234=R23×R4R23+R4                                  R234=14×1014+10=14024=356R1&R234   are in series   R234=R1+R234                               R1234=6+356=36+356=716