The Indian Railways uses a variety of electric locomotives, classified based on the type of traction (AC or DC), gauge (broad or meter), and intended use (passenger, freight, or mixed).
WAP Series:
WAP-4: Broad-gauge locomotive used for passenger and freight services.
WAP-5: Used primarily for hauling high-speed trains like the Gatimaan Express.
WAP-7: Versatile locomotive used for a variety of trains, including high-speed and heavy-haul freight.
WAG Series:
WAG-7: Broad-gauge freight locomotive.
WAG-9: Heavy-haul electric locomotive used for freight services.
WAG-5: Used for mixed traffic (both passenger and freight).
WAM Series:
WAM-4: Broad-gauge mixed-traffic locomotive.
WCAM Series:
WCAM-1: Dual-voltage locomotive used in the Mumbai area, capable of running on both AC and DC electrified tracks.
WAGC
WAGC3: High horsepower freight locomotive for heavy-haul operations.
WAG9H:
WAG9H: High horsepower freight locomotive for heavy-haul operations.
Broad-gauge: Most of the Indian railway network is broad-gauge (1.676 m), and the locomotives mentioned above are primarily used on this gauge.
Meter-gauge: Some sections of the network are still meter-gauge (1 m), and a few DC locomotives specifically designed for this gauge are still in use. These are classified into:
YAM (Yard AC Mixed): Used for shunting and short-distance passenger trains.
YCG (Yard DC Goods): Used for shunting and short-distance freight trains.
Additional classification:
High-speed locomotives: Some WAP locomotives, such as the WAP-7 and WAP-18, are designed for high speeds (up to 200 km/h).
Passenger locomotives: WAP locomotives are generally used for passenger trains, while WAM locomotives can be used for both passenger and freight.
Freight locomotives: WAG locomotives are designed for hauling freight trains, while WCM locomotives can be used for both passenger and freight.
This is just a brief overview, and there are many more specific types and variants of electric locomotives used in the Indian Railways.

