Rasi, Natchathiram and the 10 Porutham — A Plain Guide

In most Tamil families the horoscope comparison happens early — often before photographs are exchanged. If you are managing a matrimony search and are not fluent in the terms, this is a plain explanation of what is being checked and why. It is written to help you use matrimony search filters sensibly, and it is not a substitute for a reading by your family astrologer, who works from the full birth chart rather than from two fields on a form.

Rasi, natchathiram, lagnam — the three you are asked for

Rasi and natchathiram are the two fields almost every Tamil matrimony form asks for, because most preliminary matching runs on them alone. Lagnam is asked for because deeper readings need it.

• Rasi (ராசி) — the moon sign. Which of the twelve zodiac signs the moon occupied at birth. There are twelve, from Mesham through Meenam.
• Natchathiram (நட்சத்திரம்) — the birth star. A finer division of the same sky into twenty-seven stars, from Ashwini through Revathi, each further divided into four padams (quarters). Natchathiram plus padam is what most porutham calculations actually use.
• Lagnam (லக்னம்) — the ascendant. The sign rising on the eastern horizon at the moment of birth. It depends on the birth time and place, so an accurate lagnam requires an accurate birth time.

The 10 porutham, in order

Porutham (பொருத்தம்) means compatibility. Traditional Tamil matching checks ten of them between the bride's and groom's stars. Different families and astrologers weigh them differently, and almost nobody requires all ten:

• Dina porutham — general wellbeing and longevity of the union. Counted from the bride's star to the groom's. One of the two or three most weighted.
• Gana porutham — temperament compatibility. The twenty-seven stars group into three ganas (deva, manushya, rakshasa), and the match looks at whether the two natures sit well together.
• Mahendra porutham — progeny and the continuity of the family line.
• Stree Dheerga porutham — the bride's wellbeing and long life.
• Yoni porutham — physical and intimate compatibility. Each star carries an animal symbol, and certain pairings are considered opposed.
• Rasi porutham — compatibility of the two moon signs, and their relative positions.
• Rasi Adhipathi porutham — the friendship between the planetary lords of the two rasis. Often weighed alongside rasi porutham.
• Vasya porutham — mutual attraction and accommodation between the signs.
• Rajju porutham — the stability and duration of the marriage. Traditionally treated as one of the more serious ones.
• Vedha porutham — checks for stars considered mutually afflicting. Treated as an exclusion rather than a score.

Which ones families weigh most

In practice, most Tamil astrologers lead with dina, gana, rajju, yoni and rasi, and treat vedha as a disqualifier if present. A common working standard is that a reasonable number of the ten should agree, rather than all of them — a demand for a perfect ten leaves almost no candidates, and no experienced astrologer would set that bar.

Beyond the ten, families often ask separately about dosham — chevvai dosham (Mars placement, also called manglik in the north), naga dosham and others — which is assessed from the full chart, not from the star alone. This is precisely where an online score cannot help you, and where a reading is required.

What an online compatibility score can honestly do

Naam Vanniyar shows a compatibility score out of 100 on every profile. It is computed from the fields both members have entered — age, district, education tier, occupation, income band, marital status, and on the horoscope side the compatibility of the two rasis by zodiac element together with a simplified dina porutham reading between the two natchathirams. The profile also explains which factors contributed, so you can see what drove the number.

What it does well is order a long list, so you look at fifteen promising profiles instead of three hundred in arbitrary order. What it cannot do is give you a porutham verdict: it does not read the full chart, it does not use padam, it does not assess dosham, and it does not weigh the ten porutham the way your astrologer will. Use it to decide whom to take to your astrologer, not to decide instead of them.

Using the filters sensibly

• Enter your rasi, natchathiram and lagnam on your profile. Families that leave these blank are skipped early by families for whom the horoscope is a hard requirement.
• Get the birth time right if you enter lagnam — an approximate time makes lagnam unreliable and worse than absent.
• When filtering, select several acceptable natchathirams rather than one. The natchathiram filter is multi-select for exactly this reason.
• Run the search once without horoscope filters to see the real size of your pool, then add them back.
• Take the shortlist to your astrologer with full birth details, and let the reading be the decision.

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