One more thing I must highlight here and that is, I had a stock Baleno 99 1.3 driven only 90K and it used to give me 120 kmh at 3K rpm, unfortunately, lost all the pictures else I could share here.
So, I used this calculator shared by Zain with Baleno figures and found the reading was 120 kmh at almost 3.4K rpm which is a difference of 400 rpm compared to the real-life scenario.
However, I guess the best way to do it is to get an OBD/Scanner and then while connected give it a run on the motorway at 120 kmh and will get the actual figures then.
I asked this question to many dealerships in Karachi and even in Lahore, nobody knows the answer to that as almost everybody told me that it should be around at max 3.5K rpm at 120 kmh which does not look realistic to me at all.
I emailed Suzuki Japan as well and got no reply as of yet.
Looks like OBD/Scanner is the last way to opt for it.