> Does NetBSD 1.6.1 support Compaq Smart Array 5300? 

This is the best candidate I see for the right driver:
http://netbsd.gw.com/cgi-bin/man-cgi?cac++NetBSD-1.6

The latest version doesn't say any different:
http://netbsd.gw.com/cgi-bin/man-cgi?cac++NetBSD-current