As per the regulations by TRAI, DTH operators are not allowed to lock the FTA channel reception if the customer has withdrawn DTH services with no dues to the operator. The customer is free to use the CPE (Customer premise equipment) to receive Free To Air channels from Doordarshan or other available satellites. But most DTH operators are not providing this facility to customers. The set-top boxes provided by operators are locked; you can’t do much with them. However, LNB and antenna are general-purpose hardware that can be used to tune the signals of your choice. You can use the free-to-air set-top box to connect with this antenna to receive FTA channels.

Well, if you are already a DD Free dish user, then you can tune DD Free dish free-to-air TV channels, also you can try to tune other Ku-band satellites for adding more FTA channels to this list.

Which satellite you can scan for more FTA channels including DD Freedish channels?
You can tune SES8 / NSS6 satellite transponder frequencies, and you do no need to align your dish antenna. You will get signals from both satellites (DD Freedish at GSAT15 Satellite at 93.5 Degree east and NSS6/SES8 satellite at 95.0 Degree East). So you can point your dish antenna at 94.3 degrees east to get signals of both satellites.

I have pointed our DTH antenna to 94.3 degrees east, now which frequencies I need a scan?
You can scan your free-to-air STB by the "Auto Scan" or "Blind Scan" function, if you still not getting signals then you can put the given below frequencies in your set-top box and align your dish antenna accordingly.

Technical parameters of SES-8 /NSS6 Satellite at 95.0 Degree EAST:
Satellite Position: 95.0 East
Satellite: NSS6 / SES8
LNB Frequencies: Universal LNB (09750-10600)
TP Frequencies: 11038/ 11090/ 11172 / 12050/ 12110 / 12534/ 12595
POL:  H / H / H / H / H / V / H
Symbol Rate : 40700 / 30000 / 30000 / 45000 / 40700 / 43200 / 43200
System: DVB-S / mpeg-2
FEC: 3/4
22K: ON / AUTO
MODE: FTA

Here is a list of other FTA channels


Technical parameters of GSAT 15 satellite at 93.5 Degree EAST:
Satellite Position: 93.50 East
Satellite: NSS6 / SES8
LNB Frequencies: Universal LNB (09750-10600)
TP Frequencies: 11090 / 11170 / 11470 / 11510 / 11550 / 11550 / 11590 / 11670 /
POL:  V / V / V / V / V / H / V / V /
Symbol Rate: 29500 / 29500 / 29500 / 29500 / 29500 / 29500 / 29500 / 29500 /
System: DVB-S / mpeg-2
FEC: 3/4
22K: ON / AUTO
MODE: FTA

Here is a list of DD Free dish TV channels...