Yes, you can, but as I know Indian passport holders need to have a visa to Hong Kong. I guess you have Chinese visa?!
From Hong Kong to Guangdong, it depands on which city do you want to go. If you are going to Guangzhou, you can take the Eat Railway Line. If you go to Shenzhen, you can take metroway and bus. :-)

maybe you should consider to travel to mainland China from Hong Kong by ferry. Its very easy as you do need to go through HK custom clearance but straight to ferry destination which is within the airport itselff.Ferries goes to Shekou,Macau and believe Guanzzhou as well

i want to travel guangzhou china can i travel via hongkong which is best way travel for and how it will take for for road to reach from hongkong to guangzhou

Yes, I guess so. I know that there are direc flight from New Delhi to Guangzhou, but that's all right if you come via Hong Kong. I guess there are more flights and cheaper to go Hong Kong first. From Hong Kong aiport to Guangzhou, the easiest way is to take airport shuttle bus to Guangzhou city directly. It will coast around 220HKD. The other way is to take airport Bus A21 to Hung Hom (33HKD) and change to the East rail to Guangzhou East Railway Station (190HKD per person). The cheaper one should be take MTR to Shenzhen Luo Hu and then change to bus to Shenzhen.