After 12th,  there are 2 ways to get the HRM degree. One is directly after 12th you can apply for integrated management exam like IPMAT (conducted by IIM Indore) which is a 5 year management program- BBA+MBA.

Other way is first complete your graduation with good percentage and then appear for management entrances like CAT, MAT, XAT,CMAT etc..

Some of the good colleges for HR specialization are:
XLRI
MDI
XIMB
IIM Ranchi
XISS
UBS Panjab university

So you can try both the ways and get into the best one.

You can check IPMAT criteria below, if interested:
IPMAT-All about!

Good Luck.