In reply to mishra_almailtu:
Register sequences don’t need an explicit sequencer as they use the sequencer stored in the map. The uvm_reg read() and write() methods have optional map arguments. If you don’t specify a map, the methods use the default map.
I assume that by “register sequences” you mean sequences with calls such as rm.reg.read(…) and rm.reg_write(…). The predefined sequences, such as uvm_reg_hw_reset_seq, use these calls and the maps.