Best degree course & college for IAS

Dear frds/ experts,

One of my frd's sister have finished 12th std in Tamilnadu....she wants to do IAS.... keeping this in mind, she wants to make a degree which supports to do IAS......like B.A in civil services.....she asked my suggestions....thats y am sharing with u frds....Can u please recommend any apt course for this?? If so, plz also suggest abt which will be the best coaching college for it in Tamilnadu??
Hope u guys reply soon...
Thank u....