Hi Bahubali06,
First off, a 740/Q50 is an outstanding Score, so you can comfortably apply to any Business Schools that interest you. As such, a retest is not necessary. With highly competitive Schools, it's important to remember that beyond needing a strong GMAT Score (which you now have) you also need a strong OVERALL profile AND you need to properly 'market yourself' to each individual Program that you apply to. As such, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement (and in simple terms, your time and energy would likely be better spent improving other aspects of your application than trying to improve what is already an outstanding Score by a couple of points).
There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/GMAT assassins aren't born, they're made,
Rich