is there a bus to ride which will bring us directly to ocean park if we are at the peak ?

I'm afraid no direct bus can take you from the peak to the Ocean Park. You have to transfer. Here it is: At the Peak( Public Transport Terminus), you can take bus no. 1 to Central (Hong Kong Station Public Transport Interchange), from where you need to walk to Central (Exchange Square) to take bus no. 90 or 97 to Aberdeen Tunnel Toll Plaza. After that, you can walk to Ocean Park. The whole journey takes 70-75min and costs 13.9HKD.

Comparatively, it is easier and time-saving to go down the peak by peak tram first and take bus no. 629 at Central Pier No.7.