This is a seal on a porcelain piece. I am not sure if it is from China or Japan. Can anyone tell me what it says? (Characters identified: 大明嘉靖年製)
From right to left, up to down:


大明嘉靖年製
Made during the Jiajing era of Great Ming


大明 is the official name of the Ming dynasty. 嘉靖年 refers to the Jiajing era (1521–67). 製 is a verb meaning 'to make', here it is passive. So assuming this not being a counterfeit, it is from China.

An old character for 明 is 朙 (seen here), which is frequently adopted in seal scripts.