Dinesh, which version of MA are you using? In general as from MAS8.9 you need to enable the MASDD external systems to import / export IoT data. Ideally you have created devices and metrics in IBM MAS Monitor or WIOTP. When associating an asset meter with one of the IoT device's metric, and MASDD enabled, you don't need to activate the IOTCONNECTOR and data is streaming in. As form MAS9.1 even the MASDD (Asset Data Dictionary) isn't needed anymore and IoT Data (via asset meter and metric) is automatically streaming in.
As from MAS9.1 you can directly setup a metric / asset meter connection in either Manage or Monitor.