The correct pronunciation of "Ghibli" in Japanese is approximately "gee-blee." Here's a breakdown of the pronunciation:
First Syllable "Gee": Pronounce the "G" sound like the English "g" in "give" or "go." It's a hard "g" sound.
Second Syllable "Blee": The "b" sound is pronounced as it is in English. The "lee" part rhymes with the English word "flee."