According to TABLE 2-10: DEFAULT PARAMETERS FOR CHANNELS of RN2483 (http://ww1.microchip.com/downloads/en/DeviceDoc/RN2483-LoRa-Technology-Module-Command-Reference-User-Guide-DS40001784G.pdf)
The first three channels are fixed at 868100000,868300000,868500000, the others channels can be set to appropriate Indian Frequencies according to LoRaWAN Regional Parameters using mac set ch freq command, but ABP works good but For OTAA even after setting the DevEUI , AppEUI and the matching AppKey , when I try to join using mac join otaa : it responds with no_free_ch.
What can be done to use OTTA?