The abbreviation BHK stands for bedroom, hall, and kitchen. It’s a metric for expressing the number of rooms in a building. A 2BHK, for example, indicates that the home contains two bedrooms, one hall, and a kitchen. A three-bedroom, one-bathroom flat has three bedrooms, a hall, and a single kitchen. Even if there are two bathrooms/toilets, sellers may or may not promote it that way, but the number of bedrooms will always be mentioned.
1BHK is 1 bedroom, hall, kitchen
2BHK is 2 bedrooms, hall, kitchen
3BHK is 3 bedrooms, hall, kitchen
4BHK is 4 bedrooms, hall, kitchen
All of them have a bath and toilet space, even if the acronym does not include a ‘T’ as in a toilet space. Some vendors may advertise their home as a 3BHK+2T home. The term “2T” here refers to two toilets. This is done to emphasize the advantage of having more room.