I have a Bangladeshi passport but is currently living in UK with a student visa. Can I enter Turkey at my transit without a Turkish visa? I will be travelling with Turkish Airlines and have a layover at Ataturk Airport. I also read somewhere that Turkish Airline offers city tours in long transits. Is that true?
As stated in the website of Ministry of Foreign Affairs of Turkey, ordinary Bangladeshi nationals are required to have a visa to enter Turkey. However, since you have a UK residence permit, you are eligible to apply for a single entry e-Visa which is valid for one month.
Turkish Airlines, does offer guided tours in Istanbul for layovers of at least 6 hours. You can find more details on How To Apply on their website.
As stated in Timatic, the database used by Airlines:
Visa required, except for Holders of normal passports issued to nationals of Bangladesh holding a visa valid on arrival, issued by Ireland (Rep.), USA or United Kingdom or a Schengen Member State can obtain a visa or an e-visa on arrival, for a max. stay of 1 month. Fee: USD 30.-, EUR 25.- or GBP 20.-. The e-visa can also be obtained online prior to departure at www.evisa.gov.tr.
So you can either apply for an electronic entry Permit HERE, or you can get it at a Kiosk at Istanbul Airport.