Dear Mohit,
Had there been State-ST quota in your state's NLU you would have been able to get a seat there. For a ST candidate with AIR 19000 it'll always be tough to get a seat without State-ST quota.
Don't get disheartened by not getting admission in any NLU. There are other options as well.

You can do BALLB from The Tamil Nadu Dr.Ambedkar Law University, For prospectus follow the given link Last date for form Submission @ TNDALU is June 29 .

You can also do Five year LLB programme from SGGSWU Fatehgarh Sahib (Last date Aug. 14). Both Universities give admission on the basis of marks obtained in Class 12. I hope it helps.