Overview
The TM660M-A2 is an uncategorised made by Nvidia with 1296 pins.
PCBKit's library has its footprint (bga-1296-23x23mm-layout36x36-p0-6mm:BGA-1296_23x23mm_Layout36x36_P0.6mm, from Antmicro), ready for a KiCad board.
Symbol
The library has no symbol for this part yet.
Footprint
Questions
Is there a KiCad symbol and footprint for the TM660M-A2?
Yes. the footprint bga-1296-23x23mm-layout36x36-p0-6mm:BGA-1296_23x23mm_Layout36x36_P0.6mm, both drawn on this page. PCBKit places them on a board for you when you design with it.
Where is the TM660M-A2 datasheet?
Nvidia publishes it: the Datasheet link on this page opens it.