Generally, what humans consider “one character” is hard to define. A single character is called a grapheme, and there are some conflicting definitions. (It’s even language-dependent: for example in my native language, Czech, ch is traditionally considered a single character.)
Python itself doesn’t work with graphemes, but a quick search shows that there’s a grapheme library on PyPI, which should work well for Devanagari:
just selete this word “आ ,रा, म, हिमाल” and click to Quote this conversation open in edit mode click to last character म then press left, right key (up,down,right,left key) you can see this editor support or consider रा , हि, मा, ल are one character just copy this and paste in python editor consider र, ा, ह , ि, म,ा, ल
this is just and example I am making character specific program so I need this
It is not clear what you are asking. Unicode is already defined standard for representing text. Consonants and vowels are sounds, presumably already defined in each language (nothing to do with Unicode code points).
Characters (graphemes) are also already defined in each language, albeit not well at times.
Consequently you cannot “define” any of the above, you need to work with the existing definitions.
It would help if you rephrased your question, which I assume is a Python question, using these well-defined terms.