Unless your restricted by your country it may be possible to add the Youtube app from Appworld.
do a search https://appworld.blackberry.com/webs...countrycode=US
change the country to Bangladesh to get the app for your country. there are free ones listed.
If your not restricted and the app wont load try reading these links for more info.
keep in mind, your carrier may also restrict access. A call to them to see may help. KB20491-Unable to view YouTube video file on an unlocked BlackBerry smartphone
read the bottom links KB03892-Differences in browsers on the BlackBerry smartphone