Question

how did the british in Delhi lived before 1857

Answer 1

they sell spices,many traders came to india

Answer 2

Delhi at the start of 1857 was a picturesque town of decay and ruins less than half the size of Lucknow and a fraction of the size of Calcutta. Delhi smelled of rot and sandalwood and stench and rosewater. The British  even had to create the Bridge of Boats across the river and complete the crucial canal to bring fresh water which Akbar started but no other Mughal bothered to complete.The city was segregated   with strict apartheid to placate  prickly religious and racial elite castes who religiously and ritually could not endure contact even upwind by degraded racial and religious inferiors. Jobs also created segregation. Westerners were expected to obey  segregation and apartheid which was both religiously enforced by the Vedas of Varna Caste  and sharia law as well as culture  and unspoken understanding. The Westerners tended to cluster in districts around banks and mostly clustered outside the British built city walls on the ‘Ridge’ or high rise of land where they built bunglaows and georgian cottages and follies. Cricket greens and polo fields were in this area. The British rebuilt city wall was some 30 feet tall, plus a dry moat, and narrow bridges under bastions with artillery. In 1857 the British would ironically besiege their own rebuilt walls and artillery guns.  Delhi reflected the irony of Mughal Rule which never invested in infrastructure other than forts and palaces and the British who brought infrastructure, metalic (tarmac) roads, steel bridges, canals, and offers to build sewers  (rejected by the Delhiwallahs). Delhi knew that by 1818 it’s economy was bust and since 1818 the British brought money, income, and the scary promise of a railroad to Delhi in 1859 to link Delhi to Calcutta. Delhi was torn between nostalgia for the Mughals who ruined Delhi and the new rich  who wanted Western modernization and global trade to kick-start Delhi.
The bungalows of the Ridge were smallish and low laying, draped with grass woven mats kept sodden with water to cool the dark interiors in summer and also deep cool rooms dug deep underground.  The British tried to recreate the cool greenness of their home but Delhi was a hot and extreme climate, clammy and foggy in winter, and up to 120 in summer with monsoon rains for two months in between. The Ridge was burned on the first day of the arrival of the Rebels but the Rebels fatally failed to realize that the Ridge was the high ground and in any battle the winner usually plants his bony rump on the high ground. Too late, Mirza Mughal tried to haul cannon and soldiers to the Ridge as early battles with the British caused a rout — with royals leading the retreat back into Delhi. Meerut Moronas occupied the Ridge for a month just to keep the Rebels off it. Thus, John Nicholson’s Mobile Column and Siege Train could arrive to the high ground to start the siege of Delhi. The failure of the Rebels to take the Ridge for a month when they could would prove fatal.