Hi,
I am working in Yangon, luckily i ussually apply visa for our staff.
Yes, with 6 months visa, they called it is a Multiple business visa. In this 6 months, you can re-entry to Myanmar as much as you waint. If you are living in Myanmar, as a foreigner, you need a stay permit (FRC).
Befor extention day (1 month) i will apply for extention visa for next 6 month.
If you apply multiple visa out of Myanmar, your passport need at least 1 or 1 times with business visa.
But if you alredy in Myanmar with Business visa, you can write the letter to ask for stay permit and multiple visa for 6 months.
Because we work with Ministry of Hotels and Tourism. We write letter to This office and MOHT write letter to immigriation to issuse the stay permit (multiple visa 6 months) for us.
It a but complicated, but if you need more detail information, you can call me viva : 0925 25 92 818. I will help you if i can.