Gst on manpower supplier under rcm who is not corssing 20 la

As such manpower supply is not under RCM, under GST

But, when supplier is not registered under GST (say, because of limit 20L); and if Service Receiver is registered under GST........ The liability to pay GST is shifted over Service Receiver....... and thus the supply comes under RCM !!!

Thanks a lot Sir for your reply

Also please let me know if ITC available for such GST payment ? 

Yes, ITC can be availed on RCM payments..