The way Marathe talks to Madhu, leaves her in a state where she doesn't know how to react.  Madhu is willing to do anything and everything for RK even if her morals don't allow her. She desperately looks out for ways to see RK out of the jail. Marathe sees that desperation and asks for 20 crores to weaken the case. Madhu is in shock, she shares this with everyone at RK mansion and is too stern that she will get RK out no matter what. 

Ultimately when she remembers the stubbornness which she saw in Marathe's eyes to destroy RK, she is left with no option but to agree to his condition even if her morals didn't allow her. Joshi always had a soft corner for RK since the start, he secretly gives RK his phone making him speak to Madhu.  But they have only 10 minutes. 

Madhu and RK are in their own world when they get to talk to each other. They get emotional and at the same time there is pain in their eyes. They don't even realise when those 10 mins get over and Joshi comes back to take the phone.