Hi Himanshu,
Since you've studied for just 1.5 months so far, there's a pretty good chance that you will naturally improve over the course of the next month. However, to hit your goal score, you would have to perform at a significantly higher level in all 3 Verbal categories (SC, RC and CR) AND in the Quant section. As such, you will almost certainly need far more than another month to hit that score level.
You asked how you might have scored if your wrong answers were more 'spread out', but that's a tricky question to try to answer (since the Official Scoring Algorithm involves more than just the number of correct/incorrect answers). In addition, since RC questions come in 'groups', it's not reasonable to think that you could have controlled which RC questions you got wrong.
Since you're not on an immediate application deadline, I would suggest that you focus on the immediate issue at hand - locking in a competitive GMAT score (even if that means extending your studies). If after the next couple of weeks you have not seen any meaningful improvement in your scores, then you might need to invest in some different study materials and learn/practice some new Tactics.
GMAT assassins aren't born, they're made,
Rich