Root on A string
no fifthx3243x
Cmaj9 is the C major 9 chord. Its notes are C, E, G, B and D. A major seventh plus a ninth. The compact grip omits the fifth.
x3243x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every C, E, G, B and D on the first 12 frets. The filled dots are the root, C. Build your own shape from any nearby group.
Other C chords
Other major 9 chords