A Model 36 is a Smith and Wesson. On the right side, in front of the trigger, and below the barrel, it will say
Made in USA
Smith & Wesson
On the LEFT side, directly below the cylinder release, it will have the S&W logo in a circle, and trade mark, and reg. US pat office
However, I think yours may be a Charter Arms Undercover. That is not a model 36 (J frame is S&Ws designation of that frame size and shape) However, Charter followed the S&W shape pretty closely, and J frame grips should fit. DO NOT expect other S&W parts to fit your gun if it is NOT a S&W.
PS- Your caliber marking may say .38 S&W Special. That is the CALIBER, not the make.