chencp2003,
If I am you I would get a PCC from the place of residence (which is mentioned in the Ration Card).
The logic I follow here is:
If you had lived in any other country outside of India, let's say UGANDA for instance, you get a PCC from place where you resided (most or last) and not from every state/province in which you lived in UGANDA for more than a period of 6 months.
Again, this is my logic. Going by that, one police certificate should be enough.
The worst case scenario:
The officer at the US Embassy 'DOES NOT HAVE DISCRETIONARY' powers to reject your immigration outright. All he could do is say that you need to get a PCC from Bangalore. Since you are working in india, it makes things really simple. You just go talk to SP of the Banglore region, explain your situation and get a PCC and come back to the Consulate and get your I.V. stamped.
BTW, have you got your PCC from Chennai? If so, where did you get it from. (I need it for my wife). Also could I ask you where your permanent residence is? (Just to decipher which Commissioner's office's jurisdiction your residence falls under!). My wife had approached the Commissioner's office at Marina Beach and they told that PCC will be issued only at the local police station and she had gone to her PURASIVAKKAM police station and got it signed by the police inspector. I don't know whether that's acceptable.
Does anybody know as to who the authorized signatory for the PCC? (is it SP and above or anybody authorized person from the PD could sign?)
Hope this helps.
Cheers,
Ganesh.