The Vicky Donor producer told The Times of India that he had an instant connection with the investment banker, who he reportedly met last April.
"I met Priya through a common friend," Abraham revealed. "There was an instant connection. I can talk to her about anything. Ours is a very honest relationship. We can tell each other everything. That's a benchmark for a healthy relationship."
The 39-year-old actor confirmed the marriage would take place this year and that it would be a small affair.
Abraham added: "I know it will be this year, but I don't know when. It could be in a few months or a few weeks. I am a very impulsive guy. So I might decide to get married next week! It's possible that our wedding may have just 10 people, if we include close family."
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The Force star also revealed that the couple will have a civil wedding, describing himself as "an atheist bordering on being agnostic."
Runchal is reportedly in London considering further study, and Abraham is said to have met her family on two separate occasions.
The actor also dismissed suggestions that they were in fact married in Los Angeles a few months ago
Abraham said recently that he intends to have children soon after he is married.