My friend is about to begin a RCIA course in view to be received at Easter next year. As I have done part of the course at a different church but within the same diocese - in Easter will we be able to be received at the same church in Easter as I don’t want to be separate.
RCIA is typically done in a parish rather than a region or diocese. Part of the RCIA process is the process of becoming part of a parish community, not just the Church as a whole.
In my experience as an RCIA director, I’ve only had one time that someone went through RCIA in one parish but received the sacraments of initiation in another, and it was a very exceptional circumstance. A woman started RCIA in our parish. Her example then prompted her brother, who lived in another city, to also start RCIA. The brother and sister wanted to be at each other’s baptisms, and their parents wanted to be at both as well. His RCIA director and pastor worked with my pastor and me to make sure everything worked smoothly to have him go through the final preparations on Holy Saturday and receive the sacraments at the Easter Vigil. And, of course, even though he hadn’t gone through the other rites with us and didn’t know any of us except for his sister, we wanted him to feel welcome and be able to celebrate this major day in his life. At the same time, I felt sorry for his RCIA team, fellow catechumens, and parish community who couldn’t celebrate this joyous occasion with him.
With all of that said, I can’t help but think your question sounds a bit misdirected. Which parish community will you be part of? If your friend will be part of one parish and you’ll be part of another, what difference does it make if you receive your sacraments together? Wouldn’t you want to receive them with your parish community, your RCIA team, and your fellow candidates? If the most important thing is for both of you to be together, then why not go through RCIA together?