NIOKR contract is exactly that, a contract for a NIR, and an OKR. НИР (NIR) is научно-иследовательская работа (scientific-research work). ОКР (OKR) is опытно-конструкторская работа (trials-construction work). The first represents development on paper, on a computer, in a lab, etc. The second represents building physical prototypes, testing, modifying, etc. A НИОКР is both. So the MoD has just funded development of the program up to but not including state trials. Whether this means they will buy it or not, is anyone's guess. Especially these days.
37 MiG-35s doesn't sound right. There is news that a contract for 24 is about to be signed. That's all I've read. I doubt 37 is the right number, since squadrons are still 12 birds.