TISS or Tata Institute od Social Sciences is suitable only if you wish to pursue a career in HR. It has a very low batch size of around 60-70 participants and only has the HR program. However SIBM has a PGDM program which will help you pursue any domain you want like finance, marketing, operations or HR. So, it actually depends on what you want to do. Apart from that both the colleges are the same with regards to placement. Since SIBM has a larger batch size than TISS the number of recruiters visiting SIBM is more.