Mohawk is a major indie music venue in Austin, situated on Red River street, which is the second major artery of music venues in the downtown area. It is next door to Cheer Up Charlies and lies within shouting distance from Stubb's. It does not look like a particularly large place from the outside, but that upper deck facing the stage helps them pack more people than one would expect. There is also a smaller indoors stage for smaller acts. It is a relatively new venue, established in 2006, but became a major spot in the city, and has been serving as one of the key venues during SXSW. They are not locked into any particular genre, but the place has very strong indie vibes, between the overall decor and the types of artists they typically book.
For the inside stage, it is typically by the wall opposite the stage. For the outdoors, it is by the outside bar.
In the atrium, which lies between both stages, on the opposite side of the main door.
There isn't much parking specific to Mohawk. There are lots nearby though, see 12th and Red River. Park anywhere nearby. There is a lot by 12th and Trinity.