Is there any site where one can check NLGI number for grease of various companies and select one on the basis of own requirements, like for HV motors etc.

Hello,
The NLGI scale will only allow you to understand what the consistency of the finished lubricant will be. It in no way will allow you to determine if the product is suitable for any application. Additional information is required ie the base oil viscosity of the product and the associated performance charactistcs of that base oil. All of the grease manufactures will have posted on thier sites or product information books recommendations for what they recommend. You can make your own list and then do a comparison to see what makes sence for your application.
regards.....

NLGI Nos. are standard specified by National Lubricating Grease Institute, USA and are used internationaly.They only specify the grease consistency or how thick or thin the greaseis.
It does not tell you its suitability for particular application.You have to consider various other factors for same.
The names of vaious grades of greases indiacte the NLGI no.e.g.Castrol AP-2 is NLGI 2 grade.

For any specific grease you want to compare you should get the data sheet for the grease from the manufacturer, which is often easily available from the mfr's web site. (Not the MSDS, the Product Data Sheet). There you will find the actual penetration test value. Compare to this chart: http://www.greasedispensing.com/ref-viscosity.html
and you can tell whether it is a "light #2" or a "Heavy #2", etc. This same information is also available on wikipedia or directly from NLGI.

As someone else posted, this is only viscosity information, not to be confused with lubricity, high temp. performance, etc.

Ken