Last month in BOM OCI were first sent to the 'foreigners' queue which took its dear time as people were just plain stupid to use the fingerprinting machines. (Worked for us on the first attempt, I guess the practice at the US border helps). As the 'Indian' counters were idle, someone from the BoI came over and started yelling 'all OCIs can use the Indian counters!' so all OCIs ran over to the 'Indian' counters. So if they want to they can take care of OCI at the normal counters. My family had to update their new passport numbers and fingerprints this time, in my case all went quick (only one finger scanned) as I had already come in a few times since 2020.