Pros
If you any know anyone in top management like TL, Managers then you will definitely get quick promotions, recognitions and better hikes. And if your kin is in top management or interview panel definitely you will be selected irrespective of your performance in the interview. And no policies which we need to follow comes into picture at that time.
Cons
It's very hard for an employee to survive in the company unless and until if your kin is in some higher position or you need to be someone's favourite who is in top level. The work and contributions done by you will not be counted unless and until you keep on poking them and reminding them about your contributions if you don't have a supporting manager or TL. But whereas few ppl will be there if they don't go beyond expectations and do normal work also they will be given timely promotions and recognitions, awards etc.