Hi Cristian!
SWIP/RWHOIS/ARIN/RIPE is what can be read from the relevant Wikipedia pages. How can I ask my provider about this?
You just ask. Only they can do it, so ask if they are willing to change WHOIS records for your IP(s).
My recommendation is to ask if they offer WHOIS reassignment first, then ask if they allow Tor exits, then buy.