Duniya ki yahi rasm hai दुनिया की यही रस्म है

Duniya ki yahi rasm hai, Rumi ho ya Shaami 

Sultaan ki ghulaami, kahin mulla ki ghulaami

दुनिया की यही रस्म है - रुमी हो या शामी 

सुल्तान की ग़ुलामी - कहीं मुल्ला की ग़ुलामी 

The poet says: 

These are the ways of the world -

Everyone is bound in some kind of slavery -

Either in the slavery of Shami - kings and ruling authorities

or the slavery of Rumi - the religious authorities and leaders. 

Surprisingly, No one truly wants to have freedom.

Rumi     =   Hazarat Rumi - A Sufi Imam or Maulavi (Muslim Priest)

Shaami = of Syria  

in Biblical times, Arab, Egypt, and many other neighboring countries were ruled by the king of Syria. The whole region was known as Shaam. 

The laws, language, and the subjects of this region were called Shaami.

Shaami, in this context, simply means under the rule of a king or a person of authority.