Works for me on Ethiopian (which is who I fly probably 90% of the time internationally). I have used the mobile barcode to get through the security barriers at BOM.

Good to know. I've tried it so far on KL, AF, VS, AI, EY, EK & SQ. None of them have worked.

Last few international trips had me arrive at the airport very late so only managed to get the biometrics done at BOM last night. Went to the Business/First counter as the FTI-TTP Biometric Enrolment counter was unmanned.

I asked the very nice immigration officer at the counter whether I could enrol, and she walked me to the counter but was unable to log into the system. She asked me if I could wait a few minutes and then proceeded to pester one of her superiors to leave his counter after he was finished with his passenger, who then did the biometrics for me in a matter of minutes.

the lapse happened to me too but I applied for free and got approved with a letter

Congrats! Did you apply from India and how was the sign up process? I am unable to get any OTP on my US or India number when I try it from India, getting a generic error message. A buddy tried on my behalf from US and he was able to get me an OTP. Couldn't enter the OTP as that field is disabled here.

Anyone did Biometrics at HYD ?
 

Anyone did Biometrics at HYD airport? Is that even opened? I selected HYD for biometrics and currently awaiting approval with travel in December (OCI basis). Been a Nexus (with GE and TSA pre) member and hoping to have similar experience. Let's see.

Mobile boarding pass
 

I have got a boarding pass from TG and when I reached the immigration counter the guy said, "Should I stamp your mobile phone screen? We have to stamp the boarding pass". Thank fully the guy was on the younger side and he was nice and said that I can come back with a printed BP and he will allow me to jump the queue. I had to sprint back to the airline counter and back and when I signalled to him he gestured to lift the ropes, people waiting in the huge line looked at me as if I was some celebrity they couldn't recognize or something :D

I remember last year around this time I took TG with a mobile boarding pass all the way till immigration (no check in bags) and once I reached the window, the guy said "Should I stamp your mobile screen?" but he was nice and allowed me to jump the queue when I returned with a printed boarding pass.

So long story short: Even if you do manage to get one, it's no use as you will have to get a print out for stamping at immigration

As a data point, e-gates on arrival still not functional at BOM. Immigration officer said they will only open in early December.

data point for BLR T2, e-gates are setup and ready but the officer mentioned it will be open to usage "soon".

I was able to register biometrics though. Before queueing up I asked the security I wanted to register biometrics, he called the officer responsible for it from his office and they took me to the dedicated line to register.
After registration I was sent to the regular immigration line as the gates are not open.

Registered in Bangalore. Gates not open yet
 

Registered by giving fingerprints and photo in Bangalore on Nov 11. Gates are in place but cordoned off. Not sure when they'll open

Any update on BOM arrivals registration? And if the gates have any schedule for operational launch?

I'm flying in with my wife (OCI) in a few weeks and we'd like to get her biometric registration done at that time.

Registration at arrivals is functional as usual. Saw the counter open at BOM arrivals last week.

Great - where specifically are they? I think someone had said they were on the left near the Pakistani passport processing area but can't find that now.

Far end of the immigration hall after the eVisa counters. However, you are first asked to clear immigration. During immigration, ask the officer for TTP Biometrics and they will usually call someone to take you to the TTP counter to assist.