Prashanthi nilayam express will come to 3 rd platform and MMTS arrives to platform #1 , you need to go to PF#1 where you have the MMTS ticket counter on the way left to the exit, There is no probs even with family, it is safe, well if your train is late , still you have train at regular intervals, but best way is to catch MMTS as rush will be less and more over you will directly land up in SECUNDRABAD station.
if your train is too late generally it is 30 min late, and if you miss this train you can catch SC-GNT at 7.40 at SC.