You can use them in a casual way (daily conversation). These particles are used simply to show emotional expressions. ● Sih = just like the English "really?" it can be used to emphasize the question or to express disbelief or annoyance. For example: Masa, sih? (really?) Nggak juga, sih. (not really) Or sometimes it can be like this: Ngapain, sih? (what are you doing, actually?) Maunya apa, sih?! (what the hell s/he wants, actually?!) However, "sih" has lots of meaning depends on the context and tone. ● Nih = a slang form of "ini" (this), while Tuh is a slang form of "itu" (that). ● Kok = to make sure about someting. Example: Dia baik, kok. (don't worry, he's a nice person) Deh, Dong, Lah, Lho = most of these particles are only used to emphasize. But sometimes it can be meaningless too.

Sih falls into the category of phatic expression. It has no meaning. To understand how to use this, I made an article on my blog about this. You can read it here: https://www.pakguruiman.com/2019/08/the-meaning-of-sih-in-bahasa-indonesia.html Nih is informal for [ini] = this. I made an article about this on my blog with examples from movies so you can understand it better. You can read it here: https://www.pakguruiman.com/2023/09/nih-meaning-in-indonesian.html Kok is used when you want to ask about something, like, "Kok bisa? Kok belum pergi juga? Kok belum makan?" I also made an article about this on my blog with examples from movies. You can check it here: https://www.pakguruiman.com/2023/10/kok-meaning-in-indonesian.html I hope my articles will help you in your journey of learning Indonesian. Cheers.

Dinda explained them well. I agree with her. Those words are just slang/ informal language. In the formal writing you should not use those words.