Can total deductions exceeds the Gross Total Income (GTI)?
Deductions provided under Chapter VIA of the Income tax Act, cannot exceed the Gross Total Income (GTI). Income here means all the income accumulated in the GTI and reduced by the incomes mentioned below.

Long term Capital Gain (LTCG) under section 112 of the Act
Long Term Capital Gain (LTCG) under section 112A of the Act
Short Term Capital Gains (STCG) under section 111A of the Act
Incomes referred to in sections 115A, 115AB, 115AC, 115AD, 115BBA and 115D
Casual incomes like winnings from lotteries, horse races, etc., under section 58(4) of the Act.