A man [begger] lying on road [seems he will die] whom to contact so that he gets medication,

Hello friend:

911.

excon

You call 911 and police will come, depends on what they will do
1. just move him to side of road
2. drop him off at a bus or subway station
3. drop him off at a shelter
4. take him to a mental health hospital
a. the hospital can evaluate and if needed give temp help. Once on medication he is released to out patient, he then stops taking his meds, even sells them and in a week or two is back to the same problems.

*** assuming this is in the US.