Hello,
The advice I am going to give might be a bit blunt. Please understand that my intention is to help you here.
I see you are a non-native speaker and have perhaps not used English as the first language of instruction at school. There are some glaring errors you have made (ignoring the "verval" in the subject line of the post as a "typo"). Such as "my main area of lacking is", "i gave the test", "in second time", "380 only", "i have gave" - apart from others such as missing articles, absence of punctuations etc.
1. I would suggest you sit down with a basic grammar book for about a month and try practicing the theory through simple sentences. This might take a few months (which means you might need to push out your GMAT to a further date).
2. Permutation-Combination and Probability cannot be the reason for a Math score of 34. So again start with a basic math foundation book and work your way through each topic.
At the end of it do consider joining a GMAT Test prep course. More than what they teach, the advice and support you will get there would be invaluable (ofcourse subject to joining the right course

).
Arun
PS: I am assuming you are looking at atleast a 500-600 score. If your aim is lower than that then the advice might not hold true completely. But this advice will still stand you in good stead since even post-MBA good communication skills (written and oral) would be imperative for a career in business.