Parivartana · Two planets exchange signs

Parivartana yoga is mutual reception. Two planets each sit in the sign the other rules, so each is a guest in the other’s house and each holds the other as its dispositor. The tradition reads this as a firm two-way tie between the two houses those planets own, a link that runs in both directions rather than one.

What the tie is worth is decided entirely by which houses exchange, and the classical texts name three types for that reason. Mahā parivartana forms between the lords of good houses and is read as the fortunate kind. Khala parivartana draws in the third house and reads as mixed, help braided with friction. Dainya parivartana pulls in the dusthānas, the sixth, eighth, and twelfth, and is read as the difficult form, an exchange that trades one trouble for another.

A sign-exchange is only ever as good as the two houses it binds.

So the yoga on its own settles nothing. The tie is real, but it carries whatever the houses carry, and it activates in the daśā of the planets involved. To say a chart holds parivartana yoga without naming the type is to say almost nothing.