i think to begin with, the kind of firm you work with is really important as shrobona said.. starting in a big city is a good choice as you get to learn a lot about practicalities, while you have a variety of experinces in large cities like mumbai, delhi, bengaluru etc.
but the point is that every architect is different and if one wants to work on ‘his/her’ style, concepts and philosophies, a compartively blank canvas is a necessity. having learnt the practicalities probably on a larger scale in a larger city, for one’s own ideas and philosophies to come out without much tight restrictions of space, time, etc (as in the case of larger cities), a developing city or a small city rather is a good option.