Okay so this is the source
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1235543/pdf/AJHGv69p1314.pdf, a study by Underhill from 2001
I'm guessing "VI-52" was the archaic name for I1 once upon a time?(Or maybe it was just VI-52A)
The study says VI-52 makes up the y-dna for 22 percent of the Roma population tested in the study(closer to 12 or 13 percent if it's just VI-52A). Of the 252 Roma men tested 57 were found to have VI-52. 52 of these 57 with VI-52 were from Bulgaria, but of the 295 total Roma in this study only 47 were from outside Bulgaria to begin with.
As for Roma in Bulgaria it seems they have a lot more I1 than the native population if VI-52 is I1 or even VI-52A is. I'd guess the same is true for Romanian Roma as well since many of the Bulgarian Roma claim ancestry from Wallachia.