I think its Meenal singing the 'la la' part. Short but sweet. Has she sung the title song too? Oh, TSZTSK stands for Thodi Si Zameen Thoda Sa Aasman. 😆
Credit goes to yummys: http://www.zippyvideos.com/5496786375810146/tsztsa/*yum-yum
Credit goes to KARAN_VIRANI: http://www.zippyvideos.com/9951759355963946/tsztsa1_promo/