Can we use interface in sequence library?

this is the code written in seq_lib

class wr_reset_rd extends baseclass;

virtual task body();
ovm_do( write ) #20; intf.RST_I = 1; #10; intf.RST_I = 0; ovm_do( read )
endtask
endclass

//using intf.RST_I in seq_lib is allowed?

You can, but we strongly suggest that you do not. Sequences should not have physical pin information and timing in them - you should leave this for the driver. If the RST_I pin is part of the transaction, it should be encoded in your sequence item. However, if it is not specific, i.e. a global reset, you should have a separate sequencer and driver handle it controlled by another sequence or virtual sequence.