Actually there is none, provided by default frameworks, .NET framework or Win32 or these old Microsoft.XXXXX namespaces. You are left to use a third-party library or Text-to-speech with custom voices, as the native ones support English. Even if there is an Indian support, it is
English-Indian accent[^]!. First of all, the Indian (including Hindi, Marathi or others) text cannot be understood by the computer (neither can be English). The frameworks provided by .NET (for example) are written to understand the English words and sounds only, they are programmed in a way. They break the words in sounds, and then generate the sounds to be spoken.
In case of any other language, such as Hindi. You would need to re-write the same code that Microsoft team did for English. I have no experience writing Text-to-speech libraries, but the process can be done in a same manner for any other language.
You can Google for a library, there may be a free library, or a paid version of a library that you can use to generate speech for text in Hindi. I will leave the choice to you, here is a Google search for "
Text to speech indian voice[
^]".