Sasi27:
Thanks for reaching out. Addressing your questions one-by-one:
Q: Is too late to do MBA for my age?
A: No, 30 is a fine age. You are above average in terms of age but still within the normal band. I would not postpone to another year if you can control it.
Q: I am very sure I will finish my exam and get my degree. Will this be a problem to apply for MBA Schools?
A: You will have to check with each MBA school to which you are applying. When would you actually finish? It sounds like it'll work out but you have to verify with the proper folks actually deciding on your candidacy.
Q: Overall eligibility for top 20
A: Can you tell us more about your GPAs? You say they are not great, but we need to know how bad. That can be an important factor. What about the GMAT or the GRE? Have you taken either exam yet? What about any extracurricular or non-work achievements? Do you have any you can share?
We are happy to help, but need all of this information to get us to a proper starting point.