In India, the idea of specifying the kind of wedding gift that you expect from your guests is a questionable one, definitely not common at all!
But practically thinking, a gift registry is a great idea, which gives your guests the option of choosing gifts, either individually or in collaboration with other guests, which suit their budget as well as your taste and requirement. It gives you the option of asking for things/appliances that you require, gift vouchers for romantic dinners, spa treatments or for funds which can contribute towards your expenses such as honeymoon, buying your new home or wedding expenses. That being said, mentioning your gift registry can be a very tricky situation!
Generally, couples create a wedding website, which they mention on the invite and on this website they inform guests about the wedding registry. Another option is printing the registry information on invitations for other wedding related events, such as the bridal shower rather than on the actual wedding invitation. The information about the registry can be confined to a simple sentence such as "the bride and groom are registered at XYZ”
If the couple has registered at more than one store, it can still be restricted to a short line - "The bride and groom are registered at A, B and C." Instead of mentioning anything on the invite itself, you can put in an additional note explaining your decision. You can also consider mentioning what you intend to spend the money on.
Requesting for contributions towards your honeymoon or any kind of monetary gifts can be a little more complicated. If worded incorrectly, it can easily be perceived as offensive or pushy by some guests. There are many registries that have created various categories and options which are essentially disguised ways of asking for money. For example, you can plan a honeymoon itinerary which will involve various activities dinner, movies shopping etc. You can give the guests an option for paying for your movie tickets or for a dinner or for your shopping. This way you can give the guests the sense of actually giving a wedding gift!