SC rmm will not run via Tanjore they fixed via chennai and Tiruvaur.
That why Ahemdabad to Rmm was given for Thanjavur to compensate the sc train which runing as special upto trichy.
Once bridge opens it will be extended via Pudukkottai.
MDU to kcg is good but route should be old route via tirupati I don't know why they chng d that route