The standard grips this chord is usually shown with.
Eb9#11 is Eb, G, Bb, Db, F and A, a nine sharp eleven. The shape this page opens on is written xx1223, lowest string first.
Note by note. Eb is the root, G is the major third, Bb is the fifth, Db is the flat seventh, F is the ninth and A is the sharp eleventh.

Also written Eb9(#11), Eb9+11 or Eb9♯11. The same chord either way; which spelling you meet depends on who wrote the chart.
There are 6 common shapes for Eb9#11 on the guitar, and 27 derived voicings in 3 families.
One note away. Change a single note of Eb9#11 and you have Eb9 (with one note taken away), Eb9b5 (with one note taken away) or Eb13 (with one note moved).
The common shapes, written lowest string first: xx1223, x65665, x6768x, 11-10-11-10-10-11, 11-x-11-12-10-x, 11-12-11-12-11-11.
Under the hand. None of the shapes for Eb9#11 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 3 of the 6 need a barre. Together they cover the neck from the 1st fret to the 12th.
Where it goes. Eb9#11 is a dominant with its tension raised, so it still points at Ab — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
Shell. Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top. Eb9#11 has xx1021, x6566x, 11-10-11-10-x-x, x-x-13-12-14-13, xx1025, x6x025, x6x685, 11-x-11-12-10-x.
Rootless. The root left to the bass player. Frees a finger for a tension. Eb9#11 has x0302x, xx3223, xx5665, x8768x, x-10-11-10-10-x, x-x-15-14-14-15, x0x021, x4526x.
Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. Eb9#11 has x0302x.
Tensions. A shell of Eb9#11, root, third and seventh, leaves a string free, and the tones that belong over it are the b13 (Cb) and the 13 (C).
What kind of chord this is. Eb9#11 is an altered chord — a dominant seventh with its fifth or ninth moved. altered dominant chords on every root, and what they are for.
The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.