The Bastar region is located in the state of Chattisgarh, India. It is famous for its rich cultural heritage, forest areas, and national parks.

Option 1, Bandhavgarh National Park, is located in Madhya Pradesh and not in the Bastar region.

Option 2, Dandeli Sanctuary, is positioned in Karnataka and hence again, is not part of the Bastar region.

Option 3, Rajaji National Park, is a major wildlife reserve in Uttarakhand, and this park also fails to fall in the geographical realm of Bastar.

Option 4, Indravati National Park, is correctly cited as it is indeed located within the Bastar region of Chattisgarh. Hence, this is the correct answer. It is a unique natural habitat renowned for its diverse flora and fauna, making it an important part of Bastar district.