A Director General should he rely entirely on the advice of a single adviser or counselor at least two, or must possess the skills to detect sound advice and make the decision that imposes itself?

I fully agree with the answers been added by EXPERTS................Thanks.

The whole point of having a Director General is that she/he takes the final decision and takes responsibility for making it.   The smart ones usually get as much information and advice as they can from as many sources as is reasonable before making the decision.