Hi .. I have studied Vedic Maths and don't think that it alone will help you get over your quant problems. For quant, you will have to study from the regular stuff - og, kaplan
, manhattan, princeton or whatever u prefer ..
Vedic maths is extremely useful for getting super good at basic maths operations and calculations.. it does improve your speed a lot. However, it needs to be used together with the standard material to help anyone in GMAT...
Hope I've answered ur query.