It was my problem too.if you want to mimic hypoxic condition in your cell line and you have not any specific jar or incubator,is better to induction chemical hypoxia.for instance, you can use cobalt chloride.
I remember one of my friend using Oxygen scavenger (https://en.wikipedia.org/wiki/Oxygen_scavenger) to create anaerobic condition for his bacteria culture. But I don't know if it will work for maintaining hypoxic condition. Must be tricky to control the condition at certain oxygen level, even when you know the specification of the oxygen scavenger (how much oxygen can be absorbed per gram or per package).
If you want to buy a small device that will create hypoxic environment, follow this link http://www.brincubator.com/hypoxiachamber.htm. You may want to look up similar devices that may be available locally. Good luck!
This is a good method that doesn't need any specialized gear https://www.researchgate.net/publication/6344625_Inexpensive_low-oxygen_incubators. Depending on the level of control you need, you might want to add 2 sensors -- one for the air, and one for dissolved.
Thank You John Schloendorn, I have read the Protocol, sounds simple, except the Low pressure delivery system & Low pressure guage. It is very useful. Will try and tell. Thanks once again