{tabs Jumme Ki Raat}

Himesh's line, BACHAANA (likeable twist) from 2.10 to 2.12

The effort put in by Himesh to sing this song is evident as it is a no easy song to sing by any means, as it requires quick singing at high pitch and with intense emphasis.

{tabs Jummet Ki Raat - Unplugged}

The unplugged performance with slower tempo sounds quite catchy (slightly catchier than the original with faster tempo, since in original the tune is quick paced and rhythm has equal weightage whereby melody n rhythm get mixed together n go hand in hand, but with slower tempo the quick composition of mukhda is broken n slowed down to its individual portions whereby the listener can appreciate the melody quotient in it).

Himesh's line, TABAH (awesome emphasis feel with dying vocal finishing effect) from 2.43 to 2.44

Heartfelt fulltu high pitched emphasis feel singing by Himesh from 2.54 to 3.02 whereby he goes all out.

Himesh's subtle feel lines in middle octave from 3.03 to 3.19 are likeable, with emphasis on line HU HAWAAAA (awesome twist with vibrato / voice shake effect) from 3.09 to 3.11

Again lots of effort in high pitched lines from 3.20 to 3.37, with emaphasis on line KHUDKO BACHAANA (likeable twists) from 3.25 to 3.28

{tabs Tu Hi Tu}

Sung with Heartfelt subtle feel vocals, in the middle octave.

Standout lines are:

JAGAH (awesome vibrato / voice shake) 3.47, 3.54, 5.03 & 5.09, HAAI-AAAAI (awesome vibrato / voice shake) from 3.50 to 3.52, 3.56 to 3.58, 4.09 to 4.11, 4.48 to 4.50, 5.06 to 5.07, 5.12 to 5.13, 5.24 to 5.26 & 5.37 to 5.38, PUCHEE BHALA (awesome feel twist, pours heart out) from 4.05 to 4.07, KAAAAAA (awesome feel singing, heartfelt) from 4.43 to 4.44, WOOOW WOOOW (awesome vibrato / voice shake) from 4.51 to 5.00 & 5.40 to 5.49

He sings these middle octave lines in his JAANEMAN (RADIO) mode.

See the difference of scale selection what impact it has on a song. 
From start to 0.25, Himesh sings the mukhda lines in Higher scale...and from 1.17 onwards, he sings the mukhda lines on lower scale...hear the difference, on which scale the same song lines sound catchier...in my view, the HIGHER scale from start to 0.25...also, this song is very suited to Kumar Sanu's vocals, and while Mohd Irfan did a great job in OST, Himesh's version of this song would have been also good too. 

{tabs Conclusion}

It is of the view that the unplugged versions of Jumme Ki Raat n Tu Hi Tu in Himesh's voice could also have been included in the OST.