Can I get a management quota seat in KMC Manipal if my NEET score is 249?

I hate to say this but you won't be able to get a seat at KMC Manipal or Mangalore unless you have a pretty decent score and rank. Moreover, KMC Manipal has no management seats at all and the admission process is absolutely transparent. This is what sets it apart from other private medical colleges. Only the deserving candidates make it to KMC Manipal. 

There is a separate NRI quota wherein international students from the USA, Emirates, Singapore, Indonesia, and African countries apply separately.

So, there are no reserved category seats at KMC Manipal at all, so irrespective of your category, admissions are based solely on merit.