The oil capacity for 100cc engines is usually 0.9 ltr. Start the bike and go on a 10 minutes ride. After the engine is warmed up, park the bike on the double stand and check the oil level after turning the bike off. Make sure that you clean the guage after unscrewing it for the first time and then take the reading. I think that it will show low oil level. If so, that will mean that you need to add more oil.
Have you checked with the Unique authorized service man about the oil capacity as suggested by asjdsm????