A 645 on GMAT Focus puts you right around the 80th percentile, which translates to roughly a 700 on the old scale. That's a solid foundation, especially if the rest of your profile is differentiated.
The real challenge isn't the score itself. It's that Indian IT is the single most competitive demographic in the applicant pool, and many of your peers will be sitting at 675 or higher. So the question becomes: what have you done inside or outside work that an adcom can't get from a dozen other applicants with similar resumes?
A few things that would help clarify where you stand:
• Years of experience and the nature of your role (pure tech delivery vs. client-facing, product ownership, or cross-functional leadership)
• Any quantifiable impact you've driven, promotions ahead of cycle, or scope beyond your job description
• Extracurriculars, community work, or side projects that show a different dimension
If your work experience is relatively linear and your extracurriculars are thin, a retake to 665+ would meaningfully shift the math. If you've got compelling stories and real leadership depth, you can compete at strong programs in the 15-30 range now, and selectively at a few T15 schools where your profile fits a specific need. The score alone doesn't tell the story, but in your demographic it does set the threshold for where the rest of your application gets read seriously.