Hii, i want a job in which i will get postings only in the metropolitan cities?

hii, i want a job in which i will get postings only in the metropolitan cities like delhi, mumbai, calcutta, pune and so on..So what exam should i go for??Is Indian Revenue Service a good option?What are the other options?I have done my m.sc in zoology from calcutta university in 2010 with 66% marks.Plz help me out.In IAS the 1st posting one gets is in the sub-divisions.Bt i am looking for a job in which i will get posting in big cities like dilli, mumbai,pune, hyderabad, kolkata etc from the beginning.Can any1 plzz help me??Its very urgent..