Hello,

As you claimed you have given your choices of city let me tell you it's quite possible that in Chandigarh the slots have been full or you have filled the form late and that is the reason you were not alloted in Chandigarh.

Secondly, your 2nd choice was Punjab (rupnagar) but you have got a different place. This is possible only if the slots were full in that place or else NTA have allotted you the place by mistake.

You can't help with it because now you have been alloted.