never mind after looking into some samples I figured it out
If Any one want to share image with text in whatsapp they can use this....
B4X:
Dim i As Intent
i.Initialize(i.ACTION_SEND, "")
i.PutExtra("android.intent.extra.TEXT", "This is the text")
i.SetType("text/plain")
Dim u As Uri
u.Parse("file://" & File.Combine(File.DirRootExternal, "a.jpg")) '<-- change to a valid image file
i.PutExtra("android.intent.extra.STREAM", u)
i.SetType("image/jpeg")
Dim jo As JavaObject = i
jo.RunMethod("setPackage", Array("com.whatsapp"))
StartActivity(i)