
According to RBI guidelines, you will not be able to deposit money in Paytm wallet from 16th March i.e. tomorrow. In such a situation, if you are currently using Paytm's FASTag, then it needs to be changed before the deadline. Failure to do this is likely to result in over double toll charges. According to the rules, if payment is not made through Fastag, double toll has to be paid.
However, whatever money you add to Paytm wallet before March 15, you will be able to spend it even after March 15. Paytm has the highest number of FASTag users in India.
See here the process of deactivating Paytm Fastag
You can get new Fastag from banks or other UPI apps:
National Highway Authority of India i.e. NHAI has advised Paytm FASTag users to buy a new FASTag from any other authorized bank before March 15. NHAI has also released the revised list of banks issuing Fastag.
Now 39 banks and non-banking financial companies (NBFCs) have been included in this list. The name of Paytm Payments Bank (PPBL) is not included in this list. You can also order Fastag from these banks or through equivalent UPI app such as PhonePe:
Fastag KYC update documents: