The bar is of course a length of aluminium tubing (or steel, carbon, whatever) which is bent to a certain shape and that's what shape it is, you can't change that except by buying a different bar.
Bars do come in different shapes, with deeper or shallower drops, round-curved drops or 'anatomic' curves (straight sections rather than a regular round curve, supposed to be more comfortable to hold), wider or narrower, etc
If you actually mean can you loosen something and adjust the bars you've got, then yes you can loosen the bolts which hold the bars to the front of the stem and then rotate the bars up or down, which will alter the angle of the drops and also place them further away or nearer to you.
But it'll also move where the brake/shifter levers are, so depending what you're after you'll perhaps find they're now too far away or at the wrong angle for your wrist so you'll need to move them up or down the curve of the drops a bit - if only a little bit, you can do it without having to remove the bartape.
And it'll also pull/loosen the brake cable slightly so you'll have to adjust at the brake end.