咯 啦 嘞 are all modified versions of 了 that change the overall emotion of what you’re saying. You can think of them as 了哦 了啊 了诶. As for the meanings of 哦 啊 诶, they can be really subtle, something you learn best over time through exposure. Often, 哦 feels like a reminder, 啊 feels like an exclamation point, 诶 feels like excitement. But there are lots of exceptions, and regional variation and personal style affects them a lot as well. Information from u/Qaxt on Reddit