On Mathematica 12.3.0 works fine.
ClearAll["`*"]; Remove["`*"];
RotationMatrix[Pi/3]
(*{{1/2, -(Sqrt[3]/2)}, {Sqrt[3]/2, 1/2}}*)
dasarikasi26
(KASI VISWESWARA RAO DASARI)
4
Sir, my issue was not resolved yet.
Try with fresh kernel or close Mathematica and open again.
