Aamir Khan and his family will throw a grand party to celebrate his mother Zeenat Hussain's 90th birthday on Thursday, June 13. Meanwhile, work-wise, Aamir Khan was last seen in 'Laal Singh Chaddha', which didn't connect with the audience upon its release. Presently, he has a packed schedule as he is busy shooting for his upcoming film 'Sitaare Zameen Par', …