Like gmanjesh said, it's hard to give you advice without knowing the breakdown of your scores. If your Quant score is pretty strong, I'd suggest that you work on Verbal. As I'm sure you've read, GMATPrep is the most reliable indicator of your capability.
My last try (Manhattan GMAT
TYPE SCORE ESTIMATED PERCENTILE RANK
Quantitative 44 73 %
Verbal 35 77 %
Total 650 84 %
Not too bad, but i do need more.
Thank u all.
That's actually a pretty balanced breakdown, so you'd be well served to study either section. I'd suggest that you identify the subjects that are giving you the most trouble in each section and study those. Since there are only three subjects in the Verbal section, you can make a big improvement by mastering one area.