UPDATE
So, I took the GMAT yesterday and got a score of 670 (q47 v34) i.e. a 60 point jump from my mock 3 days before the test (610). This is my highest score as compared to my mocks. I was very relaxed at the test center (which was after I got a panick attack when I realised that I have brought the wrong ID proof). These are the possible reasons that might have been responsible for the difference between my mock and the real exam score:
1. I used to give my mocks in some what worse conditions than the actual GMAT(not switching on the air conditioner in the afternoon, not eating anything during the breaks) that I think affected my mock score. So, I felt A LOT more comfortable during the actual GMAT.
2. I changed my RC strategy as well as my time management strategy for the verbal section a couple of days before the exam.
3. Had a small can of coke and a pack of multi-grain berry biscuits for my energy during the breaks. (I used to be exhausted at the end of the berbal section during my mocks).
4. According to me, the most important reason, a good amount of positive prep-talk a day before and on the day of the exam (even a bit during the GMAT). I did not study or revise 2 days before the exam, just focused on having a proper strategy.
P.S.
I found GMAT quant to be much easier as compared to the mocks I took. Although,
GMAt club tests might also be responsible for it.
Sentence correction was a bit trickier, the passages in RC were easier to comprehend.
Also, there were a couple of questions that I figured were wrong. (One definitely had some error; of the other, I'm not so sure). How do I talk to the GMAC representatives about that?