Hi, I bought this budgie 4 months back. The owner told me that it was about a year old at the time of purchase. I am not able to determine whether its male or female. Can anybody identify whether its a male or female. The photos are of same bird taken with and without flash.

I would say you have a female because if the white rings around the nostrils. I am not an expert but here is some great info for your to compare: https://www.cutelittlebirdiesaviary.com/budgie-genders--3-weeks-to-adult.html

I agree it seems to be a hen.