You seem to be having two issues-
To reduce oiliness, use glycolic acid
or salicylic acid
based face wash like ahaglow, saslik etc followed by a toner(skip using it in winters) then a water based moisturiser. As you have pigmentation issues also, use a good sunscreen.
To reduce pigmentation use a good sunscreen, take vitamin c
and antioxidant supplements and use a demelanizing cream . Niltan is a mild demelanizing cream and can be used for prolonged periods
. However no medication should be used life long. So i would not advocate using niltan lifelong. Hope that answers your query. Take care.