Hi Titop, if you are referring to the answer of permitting sentences, then 'silakan' is the most polite one.
Question: Bolehkah saya duduk di sini?
Answer: Tentu, silakan anda duduk di sini.
Other examples (with the same question)
Silakan makan di tempat yang telah disediakan.
Silakan minum di tempat lain.
Silakan antri di belakang.
However, even the native speakers of Indonesian often make mistakes by writing 'silahkan' instead of 'silakan'
NB: I think it is important to write questions in a clear way, so that others could understand your questions comprehensively. Have a nice day :)