Someone will be around in a bit to give you standard advice given for newly diagnosed folk. Read that really, really carefully.
But straight away I'd advice dramatically reducing all sugary and carb rich food. So all wheat and rice based, as well as sweet products are strictly off the menu. So are potatoes!
These should be replaced by green vegetables like broccoli, spinach, legumes. Watch out for carrots though as they have a lot of hidden sugars.
You'll have to research and experiment and test, test ,test to develop a good diet for your dad to get him to acceptable levels. If you can't get test strips on prescription, spend teh money yourself to find out what foods are good for your dad and which bad.
I got diagnosed as Type 2 myself after serious weight loss and my levels were much higher than your dads. Now I have reasonable control over it.
It is very hard to get used to the diet and lifestyle changes in the beginning but after a while it gets less difficult.
As a side note, and at the risk of being totally off the mark, I notice your name seems to have an Indian derivation. If so, you may be aware of a vegetable call karela. I tell you this because using it has played a part in lowering my own blood sugar levels slightly, so you may want to look into that to, and introduce it into your dad's diet a bit more. But it is a very bitter tasting food that is hard to get used to, so be warned!