I found that if we are creating task using filter then Entry in TMS:flow from is not creating. Based on TMS:flow data only, task moves to Active state.
Filter TMS:FLB:TaskTGCreateStartFlow`! push the values in TMS:flow form. This filter basically runs on the TMS:FlowBuilder (display only) form.
Now I am trying to find out the root cause of not running this filter.