Pallavan , Vaigai express mostly (95%) departs at platform 3 & 4.
Chennai Egmore- Pondicherry express/passenger also mostly(99%) depart from Platform 1.
If u come from east side main entrance no need for FOB u can directly board to 4 th platform, infact platforms 1, 2, 3, 4 all can be accessible without FOB using east entrance.
Platform 1& 2 is easily...
more... accessible close to A2B restaurant(costly but taste is good,veg) & Anjappar hotel(costly taste will be good special for Non veg). Also Southern railway both Non veg and Veg restaurant( cheap and good) available separately at platform 4.
Two Mobile Charging points available at platform 4 close to Southern Railway canteen.