It´s some verses of a famous poem by a famous Turkish poet.

Takiyeddin Efendi’ye ne mi oldu?

It’s an exceptional question. There are two question markings: the pronoun ne and the particle mi which we usually don’t see together.

olmak here means change of state, it’s an equivalent to English ‘happen’.

> ne oldu? ‘what happened?’

The dative complement tells ‘happened to whom’?

> Takiyeddin Efendi’ye ne oldu? ‘what happened to Taqi al-Din efendi?´

The particle mi makes it a yes/no question. When it is placed in the middle of the sentence the question concerns the preceding word, in this case ne.

> Takiyeddin Efendi’ye ne mi oldu? ‘is-it-what happened to Taqi al-Din efendi?’

> ‘Are you asking what happened to Taqi al-Din effendi?’

If there is a better way to say it in English, please tell me.