Can I get admission into B.Arch with a diploma in civil engineering, having cleared 3 out of 4 semesters of math?

Yes, you can take admission in B.Arch with a Diploma in civil engineering having cleared 3 semesters out of 4 semester of maths, but in other cases you may be required to appear in an entrance exam or by completing additional coursework to meet the eligibility criteria for the B.Arch programme.