Shaikh Mirza Hussain Tabrisi Nuri in his book, Najam al Thaqib says the fourty seventh name of Imam Mehdi is Khusru, and in some books it is mentioned that his name is Khusru Majus
چهل و هفتم : (خسرو)
در ذخيره و تذكره مذكور است كه خسرو نيز نام آن حضرت است و در كتاب جاويدان خسرو مجوس
Najam al thaqib, 1/185
Now I can tell you with full guarantee that this Majus is not the Imam Mehdi of the Muslims at all.