The InScript method for Sanskrit has been introduced on translatewiki.net. It needs testing and you can test it by adding to the localisations for the Sanskrit language. As you may know the Narayam extension supports three languages: Malayalam, Bangla and Sanskrit. I understand that Junaid PV is working on documentation that may enable you to understand the Narayam framework.
We would love you to test the input methods for these languages at translatewiki.net and we love it when more languages are supported by Narayam.