I think that Mallika will get the letter, she will find out Rohan's love for Nidhi... She will instigate Rohan that he can get his love & he should fight for it... Rohan will succumb to her talks... He & Mallika will join hands to create MU between Ashni... They will separate but only for a week or so... They will realise how much they love each other & get back... This can happen ,too. Just speculating,like others.
If this happens the weapon is in Rohan's hand. Say yes to her and this way he can do Mallu pardafash easily. Wonderful idea Mallu apni jaal me khud phasegi. yeh angle bhi ho sakta hae. Tab jake Dost kya hote hae Ashu ke samajh me aega.