Difference between NEFT / RTGS / IMPS ???

IMPS 

• Immediate transfer (24 x 7)
• Upper limit : 50k per day. Total 2.5 lac per month.

NEFT

• No upper limit. Transfer is not immediate.
• Mon to Friday - 8 am to 7 pm - transfer is done in 12 batches
• Saturdays - 8 am to 1 pm - transfer is done in 6 batches.
• Some charges apply (maximum is Rs 25 + service tax)

RTGS

• Meant for large transactions. Minimum amount is 2 lac. No upper limit.
• Transfer is immediate or "real time" during business hours. (usually few minutes, but not necessarily in seconds)
• Monday to Friday - 9 am to 4.30 pm
• Saturdays - 9 am to 1 pm
• Charges : Rs.30 below 5 lac. Or Rs 55 above 5 lac.