Radmila is from the Serbian / Bulgarian Радмила — rad (joy, happy) + mila (dear, beloved) — joyful and dear. Radmila is one of the Serbian + Bulgarian + Yugoslav feminine names.
Radmila is a compound name. Its parts are milŭ — each an attested element with a recorded meaning of its own.
Radmila does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Radmila reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.