In Western Music, we find that A4 has a particular frequency that is 440Hz. So it has only one sound. All the modes and scales are defined in terms of intervals. However, we find in Hindustani Music that all the raagas and thaats are defined in terms of interval. However, it seems that there is no convention. For example, Sa maybe C or C# or D or whatever of the 12 notes. That's why instruments are said to be tuned to B or C. Thus the Indian Instruments depends on Western for tuning, and giving a particular sound a particular name. But back in the old days, when the world was not seeing a globalized picture, this should not have been the case. Then what is the system of Hindustani Music where we give a name to a particular Swara? After all 'Sa', 'Re', 'Komal Re' etc. are all intervals.
NOTE: By saying "Thus the Indian Instruments depends on Western for tuning" I do not mean to disrespect Hindustani Music as I am Indian too.
Any help would be appreciated. Thanks in advance!