Confused? A Question?

I am wondering whether Akshay's sister is also involved with Akshay's betrayal. ..please help. Just forgot her name.

No, she isn't. Her name is Arpita. At least from what is shown.. she trusts and admired Kanak over her brother, which is why Akshay apparently hates Kanak so much. His ego is basically hurt and he is jealous of Kanak, getting all adulations and opportunities from his sister. Hence he wants to frame her and defame her in the eyes of his sister..by sending her to jail.