@asif_rn
Babusar Top, as mentioned by nukhyder, is closed till mid May usually. But its actual condition can only be updated by someone who has crossed on the same day as you intend to cross as it can snow there at any moment. So even if Babusar Top is open today it may be closed tomorrow due to sudden snowfall. The road conditions to Naran and Babusar and on to Chilas are quite good if there is no snow. Accuweather can give you a forecast of Naran and Babusar Top conditions but on ground situation can only be confirmed from people in those localities.
The other route is open year round but road conditions are not so good on some portions. Choice is yours.