Hi jain808,
To start, statistically-speaking, raising a 650 to the point that you could consistently score in the 700-720 range will likely require that you commit to at least another 1 - 1.5 months of consistent, guided study - and you might have to work on more than just your RC skills. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level. With a December 20th Test Date, you only have about 2 weeks of potential study time remaining. While I understand that you really want to take the GMAT as scheduled, if you ultimately "need" a 700+ Score, then THAT Score Goal has to come first - and you have to give yourself enough time to achieve it.
Based on the information in your prior post, I have a few follow-up questions:
1) What were your Quant and Verbal Scaled Scores on each of your prior CATs/mocks (from August)?
2) Are you planning to take the At-home GMAT or are you planning to take your GMAT at a Test Facility?
3) What are the exact application deadlines that you are facing?
GMAT assassins aren't born, they're made,
Rich