Krishna
I am not sure if you can find that out from the receipt notice.. (It may even be there as part of your letter reference in some cases)..
You can definitely find out from your I-140 application. In the first page, on the right hand side, you have a classification section (just beneath the Internal Use only section).
There, you will have a check mark on one of those options.
203 (b) (2) is EB2
203 (b) (3) A (i) , 203 (b) (3) A (ii) , 203 (b) (3) A (iii) are EB3.
Find out if you have these numbers on your receipt. If they are not there, the only other option is to look at your I-140 and ofcourse your attorney..
