let me clarify
half siblings have ONE PARENT IN COMMON.
step siblings are come together due to reunion of stepmom/stepdad i.e. step family with one of ur own parents.
sikki n RK are step bros.
-if sultan's mom is a wife/mistress of mohan kundra then sultan is HALF BRO OF RK and HALF-STEP BRO OF SIKKI.(bcoz sikki will be his half bro's step bro)
-if sultan's mom is wife/mistress of kuku bhatia then he is HALF BRO OF SIKKI and HALF-STEP BRO OF RK...
omg,i'm already confused...