Echallan is a challan in digital form.
A challan is used in in India as a receipt for payment or delivery payment at a bank or treasury. It is also a way to credit money to a bank account using a form.
Example of challan is spot traffic ticket for a violation by the traffic police which should be paid by cash, at an eseva office, or using another payment method specified inside the challan.
You will find useful information about Echallan, traffic challan, challan status and more on this website.