Do you agree that Human Resources Department could not function efficiently without support from top management?

Yes I fully support you. The top management forms the main guidelines of the HR policy. Without thesupport of the top managent the hr dept cannot function efficiently. But the top management should leave the day to day activities to the HR dept and only give the broad guidelines and provide the required finance.

you should support from top management for HR depetment because other departments will not committed to policies and procedures in the company if the HR departement is weak and unsupported

I fully agree with you. HR department is a strategic partner of ther department. If you follow the strategic HR, you have to need to follow the cost effective strategy that would be helpful to manage the top management support. Otherwise, HR will be failed to play the right role for the organization.

Its not about HR in particular but in general any department cannot sustain and fuction properly without the help of the top management. Because HR reuires administration policies and has to deal with the individuals, its more indepependent compare to any other deaprtment as its not based on money solely.