Need concerta 18mg in Chennai

Basically the title, I have a prescription for 20 tablets of Concerta 18mg that I got from NIMHANS in bangalore. Need leads on where to get it from in Chennai.
Tried Apollo pharmacies and they said they don't stock it. Indhra medicals (Teynampet) said they would stock it by next week, but I'm scared I need a backup plan. My Inspiral runs out in 5 days