If you say that engine health is fine, then either 5w-30 by Total, or preferably, 10w-30 by Caltex / Havoline.
In any case, change oil + oil filter after every 5,000 Kms or 06 months, whichever comes 1st, and also keep an eye on engine oil level. If it drops, simple top it up.
GOD Forbid, if there is excessive oil consumption or smoke from the exhaust, then switch to 10w-40 fully synthetic by ZIC. If it also does not suffice, then engine rebuild / overhaul using genuine parts, as per OEM specs, and from some competent mechanic, is the final solution.