From Nathan road, what bus I will take go to HK Disneyland ?

Either by bus or by MTR, you need to transfer. Comparatively, MTR is more convenient and efficient: At Tsim Sha Tsui (TST) MTR station, you can take Tsuen Wan line to Lai King, where transfer to Tung Chung line to Sunny Bay. There you can easily transfer to Disneyland Resort line to get there directly!

Anyway, here is the route by bus for your reference: walk from where you are to Haiphong Road, Nathan Road to take bus no. A21 to get off at Lantau Link Toll Plaza. Then walk to Lantau Link Toll Plaza/Lantau Link Toll Plaza to catch bus no. R8 to Disneyland directly!