Anyone who satisfies the following criteria is welcome to donate blood.

Age : 18 -65 years
Weight : 45 kg and above
Hemoglobin: : 12.5gm/dl and above
Blood pressure : Systolic : 100-150 mm of Hg
Diastolic : 60-90 mm of Hg
Pulse : 60-100/minute

Apart from the above, the blood bank will conduct a small screening test. Once you are cleared, you can donate blood.