Model with accuracy ~0.05 mm is simply a trash.
For manufacturing purposes it should be rebuilt from ground up. Moving it from software to software will just let it cause a never ending mess.
Anyway here is quick fix in Rhino.
Manufacturing it using RhinoCAM would do the job, but moving it to Creo and try to solidify it in say accuracy of 0.001? Not a good idea.
I can't open native Solidworks file, but i performed a reflection analysis on STEP coming from Solidworks. It's ok. Just a zone with no tangency but i think it could coming from STEP conversion. It seems that solidworks and nx manage surfaces with no respect of patches of near surfaces. And that's good.
Yes, it seems Creo is pretty weak with dealing with bad data. I've made a pretend model that mimics what the OP was trying to do.
Funny thing is, the software is quite capable of dealing with such holes if you are working with native data.
You can use flexible modeling "remove" feature to fill in holes like these very easily.
Another way is to copy and paste the surfaces and use the "fill holes" option.
Here's where things go bad: After exporting the model to STEP format and then bringing the data back into a fresh session, the IDD reports that model has bad vertices!
Now the copy surface and fill holes option no longer works.
But, as shown in the image above, the flexible modeling "remove" method still works.
So maybe there's hope but only if your geometry doesn't have big errors (and how often does that happen ? 
)
we so much want..that CREO should be the best software..but i think...PTC does not share the same vision?
There's no complete tangency on Rohit's step. No hidden visualization with white edges shows no tangency edges. I improved a little with IDD, but that tool can't force tangency anywhere. Anyway to repair a 3D file is good. For manufacturing no.
I have no excellent skills in ISDX module, but i reach a complete filling of entire surface with tangency continuity. I rebuild surfaces. Expecially near the hole, geometry was very poor. IDD isn't a perfect solution. I think that for guys of reverse enginering filling this hole is a joke. Sure it's not a 2 click work as in other software. I attach Creo2 and STEP file. There are little distorsions on my work, but i'm not a specialist.
I don't think so,In advanced surface,Creo is weak compared with NX.Creo just provide IDD TOOL to fix input data(igs/step).It's a limited capabilities tool. From Proe to Creo ,do you see the advanced surface be enhanced?
