Portuguese, French, Dutch and British colonised parts of India, but Spain, being one of the major colonial powers never did; why, especially when finding a new route to India was the reason Spain funded Columbus's voyages.
The Portuguese got there first.
Then Spain (Columbus sailing for Spain) reached new land across the Atlantic.
The Portuguese claimed that they had prior treaty rights to this new land and threatened to send a fleet to defend their rights. Spain appealed to the (Spanish) Pope, Alexander VI. He decreed the lands to be Spanish (and wrote the decree in a way that threatened Portuguese claims to India).
Portugal and Spain then hammered out a treaty, the Treaty of Tordesillas, in 1494, which granted all lands west of a line 370 leagues west of the Cape Verde Islands (owned by Portugal) to Spain, and all the lands East to Portugal.
Eventually, it dawned on the Spanish and the Portuguese that this treaty was all well and good in the Atlantic, but it did not really define the boundary on the other side of the world, so they negotiated the Treaty of Zaragoza, in 1529, which fixed the Pacific boundary at the antimeridian to the Treaty of Tordesillas boundary (This allowed Spain to colonize the Philippines, as they were on the Spanish side of that line).
These two treaties banned any attempt by the Spanish to establish colonies in India.