Hello Rohan Thacker,
This post is two months old. Have you rectified your problem? Are you able to get characters on LCD screen? What value of resistor (R4) have you connected at pin no. 3? I recommend instead of resistor, use a potentiometer. After switching on the system and burning the code, try varying the potentiometer shaft until the characters are clearly displayed on the screen. This potentiometer act as a control for LCD contrast. It gives flexibility to the user to vary the brightness from displaying nothing to displaying block patterns (which is exactly what is getting displayed on your screen).
Try this method, and reply if it works, and also if it doesn’t. I’ll think of something else.
Regards,
Ajay Maity.