Make room in the guitars first
If a vocal disappears behind guitars, turning it up is only part of the answer. Guitars often take more of the midrange than the song needs. Tightening their low end and easing the range where the words live can bring a voice forward without making it thin.
Try panning rhythm guitars wide so the center stays open for the voice, the snare and the bass. If you have a full demo rather than separate tracks, stems can give you that control: a six-part split pulls out guitar and piano as well as vocals, drums and bass.
Keep the grit
A rock vocal can be rough, strained or slightly off the note and still be exactly right. Tune only what pulls you out of the song, because strict correction can make a live performance sound mechanical. Saturation and firm compression suit the style, and a little distortion can help a voice stand up to a loud band.
Not every rock vocal sits on top. Some styles keep the voice tucked into the band, while punk and hard rock push it forward. Name the records you have in mind, since the right level depends on the style.
Let it breathe and hit
Keep the feel of a band. Drum hits and guitar chords have a natural push and pull, and locking everything to a grid can make a live take stiff. Fix mistakes that distract, and leave the movement that gives a performance its energy.
Loud guitars tempt you to push the master. A wall of sound with no dynamics gets smaller, not bigger, so keep some difference between the verse and the chorus. Check the result at low volume: if the vocal and snare vanish, go back to the balance before reaching for a louder master.
Common questions
Can I fix a band demo recorded in one room?
You can improve it, within limits. Separation gives you more control, but instruments recorded together bleed into each other. For an important release, individual tracks give a far better result.
Will AI make my band sound generic?
Not by itself. Tell the producer what must stay and compare every version with your original. Mixing your recording is a different job from generating new music: your performance stays the source.