Try this:
In[6]:= Style[
Row[{Superscript["", "RVC"], Subsuperscript["BRV", "BV", "KJK"]}]]
Out[6]= \!\(\*
TemplateBox[{
TemplateBox[{"\"\"", "\"RVC\""}, "Superscript"],
TemplateBox[{"\"BRV\"", "\"BV\"", "\"KJK\""}, "Subsuperscript"]},
"RowDefault"]\)
