Milestar tires are made by Nangkang in China.
They seem to have decent reviews, although any user written tire review done by the general public must be taken with a huge gain of salt.
They seem like a really low end tire and don't seem cheap enough to justify it. Like a 205/65R15 Milestar MS932 is $45 which is cheap but that's only like $7 cheaper per tire than most low end brand name all seasons when they go on sale.
I'd personally much rather have a used set of name brand tires than new Milestars, SOLARs, Dexteros, Dorals, etc.
There is a used tire shop I go to to have patches and plugs done and tires mounted and dismounted which sells 75%+ tread 14-17" name brand tires for $30-$35 a tire mounted and balanced. I bought a 185/65r14 for a full size spare for my mr2 there. Continental control contact or something like that basically brand new from 2015 mounted and balanced on my wheel for $32. They also let you see the tires, read the date code, dunk them in water, etc. before you buy. I would do this over buying junk cheap-o tires every day if I was in a pinch and needed some cheap tires.
FWIW the shop is called MK Services in Denver. The shop is completely owned and operated by a family of Vietnamese people.