Help me and Guide me to go from 530 to 750

I am not sure on how Gmatprep gave you such a big range of scores. could be three possibilities for this dicrepancy.
(i)Gave repeated tests every day by analysing each question. Got too many known questions in the end exams. Scores inflated.
(ii)You improved yourself by working on your weak areas strtegically. You got 530 when you started your prep. As your prep went on your scores improved. But you did some blunders in official test, and thus you got a low score on D-Day
(iii) You scored consistently in 700 range in all other tests before your D-day. And you thought you did well in official test too. But you did not see the scores you expected. (This happened to many test takers who took recently in October and early November)
If it is (iii), take a break and wait for the right time.
If it turns out be be (ii), you need not worry much. See how you can not repeat those blunders again.
If it is (i), you need to start your gmatprep strategically.
I would say strategically as buying all the books available and studying hours together may not help much.
Identify your weak areas. Improve them. Hit only where it is necessary.
Make sure it is not inflated score
Is it achievers point pune? If so, A big NO.
My friend visited them to ask about course n fee. They called him every day with some wooing offers. He eventually joined. Now, He has an opinion that he lost time and money by joing Achieverspoint Pune.
You should judge yourself where are you in Gmat Preparation? Take a new test such as Mgmat diagnostic and see where you stand.

Depends on how much score you need and where do you stand now

Analyse your strengths and weaknesses. If you struggle with SC, then Mgmat SC or if CR troubles you then Powerscore CR bible etc.

I answered this question already
If you could take Mgmat fee test and post your all your results not only your quant verbal scores, many of us here will be able to guide you.
Goodluck