here are no accelerandos (gradually getting quicker) or rallentandos (slowing down gradually) in Indian music as there are in western music.  Every beat is called a 'mātra' and, as in western music, a number of mātras (or beats) form a 'vibhaga" (or bar) and the mātras and vibhagas unite to form what is known in Indian music as an 'avarta' (or rhythmic cycle).

All rhythms in India are constructed in this way.  The tāla is an organised rhythm, handed down from father to son, and the set number of beats within each time cycle never changes.  The divisions within the cycle may change from region to region, but not the number of mātras (or beats) in the tāla cycle.  This means, if a tāla has sixteen beats, it is the sixteen beats of this time cycle that is played throughout India.  Variations on the sixteen beats may be allowed, such as a slow eight beats, or a fast thirty-two beats - but that is all; the sixteen pulse stays.  

The tāla is one of the unique features of Indian music because of its complexity and flexibility within a framework of the set beats of a given rhythmic cycle.  But, like the shrutis, or micro-intervals, these elaborate patterns, which have been worked out theoretically, might look reasonable on paper, but in practice do not work,