Thaat (Hindustani system) is a 10-parent scale classification, used only for sorting ragas. Melakarta (Carnatic system) has 72 scales, each a complete raga with fixed ascending and descending notes.
Class 6 NCERT Arts Chapter 8 Taal or Talam and Raga or Ragam in Indian Music solutions
Class 6 Visual Arts Textbook chapter 8 Taal or Talam and Raga or Ragam in Indian Music question answer
In Hindustani music, ragas are grouped into 10 Thaats (parent scales), such as Bilawal, Bhairav, and Kafi. However, Thaats are not performed, they only categorize ragas.
In Carnatic music, the 72 Melakarta ragas are complete scales, meaning each can be performed. Unlike Thaats, each Melakarta raga follows specific rules for ascending (Arohanam) and descending (Avarohanam). Example: Shankarabharanam (C Major scale) is a Melakarta raga.