1. Indicate the different versions of spelling your name in your profile: Go to "Settings" (by clicking the arrow looking down in the upper right corner), then "Profile settings" > Name information > Edit name > Add alternative name.
2. Check whether the publication is already in RG by searching for its title. If yes, claim your authorship by opening the publication. Then click on the small arrow looking down (right from "Download" or from "Request full-text") and then on "Claim authorship". See also How do I confirm authorship of my publications to add them to my profile? in https://explore.researchgate.net/display/support/How+to+add+research .
3. If the publication is not yet in RG, create a page for it. See https://explore.researchgate.net/display/support/How+to+add+research . Be careful when you add the names of the authors. When you type in a name, RG offers you the accounts of people with similar names. Select the correct one, especially in your own case. When you do not select your own account, you will not be able to add the publication.