When we first tried to find this OBD port, it was very hard to spot as it was concealed with a plastic cover. We were trying to find it under the dashboard but without any luck. After 1 hour, we were able to spot it attached to chassis near driver door.
We have found that this OBD port is only available in those Maruti Suzuki Omni (Van) which has ID 65 chip. You can use any good key coding device like Silca SBB to program a new key. Process is same as that of Maruti Alto, Zen Estillo or 800 (2007 to 2009 model)
Few Maruti Van even have ID 46 chip which can't be programmed in similar way. You can either use some key cloning device like JMA TRS 5000 or Silca RW4 to make a clone or special connector (usually available with Maruti Suzuki dealers) to make a duplicate key. If you are unable to find this port in the car then its definitely an ID 46 and can't be programmed in usual way.