Your grades in high school, 11th and 12th classes do not matter for admission to B schools.
The five schools you select before the test starts receive your scores. If you have a pretty good idea of what you want to do after an MBA, you should select those schools which will be a good fit for your career goals and where you stand a realistic chance of being accepted. I think it costs approx 30 USD to send additional score reports to each school. You can do the math and see how much you end up saving if you choose your schools wisely.
As already suggested, you can post your academic profile, professional experience details, extra-curricular involvement and post-MBA goals on the Peer Review and "Ask Admissions Consultants" forums and see what advice you get. I don't believe HR is considered a concentration in the US, but marketing is a common post-MBA function. You might want to take a look at this to get started:
https://grad-schools.usnews.rankingsandr ... g-rankingsUniversity of Wisconsin-Madison and Indiana-Kelley are considered good schools outside the top-15 for marketing.
Good luck!