KM determine recommended oil change of a regular in use car.. car standing idle longer than 2 months would also require change.. in any case for your vehicle, which ever comes 1st,6 months or 5k km, engine oil working life is ok.
Recommended oil change is at 4500km, for 2nd tuning, instead of going the full 5k., even though not necessary. since there is a lot of initial wear and tear inside the engine when 1st time driven, it would be wise to get oil change earlier so that the shillings and the wear of metal is drained out.. more often than not they can be seen in the oil drained.
preferable to use the suzuki efficient oil, which only cost 300rs more but is much smoother for drive.