Note: The following FAQ information is unclear (material is public domain and they don't allow copying).
From FAQ of that website:
Q: What is indianscriptures.com?
A: : This site strives to produce the best possible transcriptions of public domain texts on the subject of Hindu / Vedic religion, scriptures, Indian culture, lifestyle, heritage and the esoteric of India and Hinduism. This site is open to all free of cost: it is accessible to anyone and does not advocate any particular point of view, person, organization or any religious / non religious school of thoughts from India or abroad.
So, these are public domain texts. public domain means non-copyrighted.
Q: Can I use stuff from this website?
A: Our content is highly researched and authenticated by eminent universities in India. Hence we don’t allow our users to copy anything from the site partly or fully or with any variation in presentation.
So, they're not allowing to copy anything which means you should not publish the text with or without modification.
For further information about 'public domain' visit the following:
Their current FAQs are unclear and confusing as they've used paradoxical language:
- One FAQ says: "public domain texts"
- Other FAQ says: "we don’t allow our users to copy anything"
Anyway, they don't want anything copied or published with or without modification.
You can contact them for further clarification.