Mental harassment at private company

Hello Sir, I am working in a private IT/Engineering company(MNC) .This request is made on behalf of majority of colleagues in my working team against the Manager we are reporting to. 1.The manager shows discrimination to employees who are not from his state/Close circle.( It is against code of conduct inside the company, but still it is violated) 2.The Manager behaves rudely to employees, even in front of Customers.(Recently, he spoke to a woman employee inside a discussion room and after discussions we found that she is crying.Though she refused to give complaint to HR, we reported the same to them.) Both the above cases, HR and other concerned did not take any action.(we believe, it is because of the Manager's hold in the upper Management). In this particular scenario, what legal help we can get without affecting our employment?(Though people are more worried about that) If we escalate the matter to the Top management, how can be sure that action will be taken against the Manager without affecting our employment. Thanks for the answer PODUVAL