Hi aimkp,
You have an average profile. Please find below the answers to the questions you have asked:
1. Whether I should retake GMAT to improve my score to 700 level in 4th attempt as B schools may take more number of attempts as negative. B-Schools never consider number of attempts negative. They just consider your highest GMAT Score and the improvement you have gradually made in each attempt. I would definitely recommend you to retake your GMAT.
2. Whether my over age around 35 years and over experience around 12 years are not suitable for class profile of top B schools regular MBA course. Definitely, your age and work experience is more than the average work experience of B-Schools but if you can portray your story(profile) very well in your essays you can have a good chance of getting an admit. I would also recommend you to consider Executive MBA program.
3. Will doing MBA even from top B schools at this career will boost my career i.e. to help me in achieving my goal to be at CEO or Managing Director level in automobile industry in next 10 years. To answer this question, I need to go through your resume first.
You may also gauge your chances of getting admission to top business school by trying this amazing tool
https://bit.ly/1C9o2MdYou can also get your free profile evaluation done by the top Ivy league B-School grads during the webinar conducted by General Education on 3rd of May'15. For registration and more details visit our website
https://www.genedmba.com/webinars-seminars/Hope this helps.
Cheers!