Total Income is the income on which tax liability is determined. It is necessary to compute total income to ascertain tax liability. section 80C to 80U provides certain deductions which can be claimed from Gross Total Income (GTI). After claiming these deductions from GTI, the income remaining is called as Total Income. In other words, GTI less Deductions (under section 80C to 80U) = Total Income (TI). Total income can also be understood as taxable income. Following table gives a better understanding of the difference between GTI and TI:
Note: Inter source losses, inter head losses, brought forward losses, unabsorbed depreciation, etc., (if any) will have to be adjusted (as per the Income-tax Law) while computing the gross total income.
Note: If the eligible assessee has opted for concessional tax regime under section 115BAA, 115BAB, 115BAC and 115BAD, the total income of assessee is computed without claiming specified exemptions or deductions.
Source: Income Tax India’s Official Website https://incometaxindia.gov.in/Pages/default.aspx