They have multiple divisions, each has its competitors

EPC is their major sector and sub-sectors even in this, competitors could be Gammon, Shapoorji, Punj Lloyd, Engineers India, ABB, BHEL

L&T has operations in sectors such as Heavy engineering, Infrastructure, power, electrical& automation and defence engineering, it's spread over 30 countries around the world.

You have to check competitors for each sector

As infra is major sector for L&T operations
Competitors : Adani ports
GMR infra.,Rites...etc.

Most of L&T competitors in construction is in bank loan scams. ILFS is example. Engineering products, they have competition from Bosch, BHEL and many European cos. In defence they have competition from Mahindra, Tata etc

Depending what bussiness u pickup up.

But as an industrial conglomerate almost every other one is.

However L&T is a jointly shepherded by LIC, Aditya Birla, Reliance , HDFC and Goverment of India.

For that you need to watch and read more about who AM Naik is and how he is the TOP man there.

Comming back to competition....L&T competes with a lot of people in a LOT of bussinesses its main bussiness of EPCs is many others.

However L&T is building a LOT of capacity around localised private defence contractor. It also has a shipping bussiness which is a sort of an envy.

L&T is the competitive edge to shapoorji pallonji, epc bussinesses of various other industrial conglomerates.