We are almost always in favor of using fresh ingredients over dried, processed, defrocked and deflavored. We're hoping in this case, that you are asking about curry leaves, and not the imprecise, inexact, loose, inaccurate, indefinite, wooly term curry powder, which can be just about anything under the sun.

Curry leaf is produced by the tree murraya koenigii, a relative of the citrus family, which grows throughout South Asia and Southeast Asia. The leaves are widely used in cooking, and often, in much the same way that bay leaves are used. If used fresh, the leaves are fried to a crispy brown before being added to the dish. They are fished out before the dish is served. Dried, the leaves retain their fragrance, and can be used whole or ground.

You can certainly use fresh leaves in place of the powder called for in your recipe. The choice to fry them or not is yours; if you make the recipe more than once, you might like to use fried leaves one time and uncooked leaves the next and see which you like best.