Moon in Gemini
The mind processes feeling by talking about it, and needs to.
The Moon is the sign that matters most here
Ask a Western astrologer for your sign and they answer with the Sun. Ask an Indian astrologer and they answer with the Moon, because in jyotish the Moon carries the mind: how you take things in, how you settle, what you need to feel safe. It is also read in the sidereal zodiac rather than the seasonal one, and the two have drifted about 24 degrees apart.
The practical consequence is that roughly four people in five get a different Moon sign here than in a Western chart. If you were told your Moon was in Cancer, Gemini is the sign directly before it, and this is the reading jyotish would actually use.
What a Gemini Moon is like
A Mercury-ruled Moon turns emotion into language almost immediately. That is a real gift, because a Gemini Moon can name what it is going through while it is going through it. It is also why the feeling can get commentated on instead of felt.
Your Moon is in Gemini, which means your feelings turn into words almost instantly. You understand your own heart by talking it out loud, and silence too long becomes a kind of static.
How it settles, and how it strains
What settles it. Conversation, and variety. A Gemini Moon starved of new input goes flat rather than sad.
Where it strains. Restlessness that looks like anxiety, and a tendency to think about a feeling until the feeling itself is out of reach.
The birth stars inside Gemini
A sign is 30 degrees, and a nakshatra is 13 degrees 20 minutes, so Gemini holds one whole birth star and shares the rest at its edges. Your nakshatra refines this reading considerably: two people with the Moon in Gemini can be very unalike if their birth stars differ.
Sidereal positions use the Lahiri ayanamsa, the Indian government standard. The Moon crosses a sign in roughly two and a half days, so a date alone usually settles it, but a birth time removes any doubt.