This helped in connecting the ONT.You just need to enter the 12 character version. In the 16 character serial, first 8 if converted from hex to ascii should give you 4 characters. Append the last 8 hex digits to it.
It seems to be connected to OLT and PON light is stable as well.
But unable to create PPPoE or Bridge mode connection from this new ONT.
Any ideas?