Before spending a few 100 rupees on getting professional help, check this article for a quick fix.
Turn off the water supply. Before beginning any plumbing related job, turn off the water supply. A leaking shower head can be caused by clogged holes, resulting from hard water build up.
Remove the showerhead faceplate. As you’ll have to soak and scrub the parts of the shower head that have the hard water buildup, removing the faceplate is necessary.
Immerse the faceplate in vinegar for 8 hours. Take a container large enough to hold the faceplate. Fill the container with vinegar and place it inside the container.
Manually remove leftover deposits. After 8 hours, the hard water residue will have dissolved. Now, stick a toothpick into each hole of the faceplate to remove the grime and dirt. Then, scrub the faceplate clean with a stiff plastic brush dipped in Vim dishwash gel. Later, rinse it thoroughly.
Check the leak. Attach the showerhead back, turn the water supply on and the problem should be fixed!