Hello Niveditha. There are no institutes in banglore offering b.arch below 1 lakh. Some of them with the least fees are given below.

• RV School of Architecture, Bangalore
• BMS School of Architecture, Bangalore

Here is the link for all the b.arch colleges in banglore.

https://engineering.careers360.com/colleges/list-of-b-arch-colleges-in-bengaluru

Hello aspirant!  Let me to inform you that there are a few colleges that has a fee structure that is affordable by you. These colleges accept reasonable Nata scores and other eligibility criteria for admission in architecture. Some of these colleges are - dayanand sagar college, visvesvaraya university college , and few more. You can check the college along with the fee structure from the link below :

https://static.careers360.mobi/media/uploads/froala_editor/files/COMEDK-UGET-2018-Round-2-Cutoff.pdf