Hi, Mykola,

A very quick search at this site, https://www.ancestry.com/search/?name=_Gritskevich&gender=m&name_x=_1,  brought up a number of entries with the first possible surname you offered.  I actually started with this very useful tool:  https://stevemorse.org/index.html.

Though I didn't see an Ivan/John or similar name, there was a name similar to Vasiliy.  May I suggest you try the Steve Morse page and see if that brings up any results for you? 

I am replying to the group so others will not duplicate this information.
Best wishes, 
--
Barbara Sloan
Conway, SC