There are no specific forms of worship for the 27th night of Rajab to be found in the authentic books of Hadith. In fact, although some scholars have opined that Mi’raj occurred on 27th Rajab, there does exist legitimate difference of opinion on this too.  To specify a form of salah for this night without substantiation from the sunnah is an innovation (bid’ah). 

And Allah Ta’ala Knows best,

https://hadithanswers.com/there-are-no-specific-forms-of-worship-for-the-27th-night-of-rajab/

https://www.hadithanswers.com/the-status-of-salatur-raghaib-in-rajab/