You'll have to pay a semi luxury tax for the 1801-2000 to category. Starts with Rs. 25,000/- annually decreasing by Rs.5,000/- goes up to 7 years....
ie-
1st year Rs.25,000/-
2nd year Rs.22,500/-
3rd year Rs.20,000/-
4th year Rs.17,500/-
5th year Rs.15,000/-
6th year Rs.12500/-
7th year Rs.10,000/-
And for late payments there's a penalty of 50%
Normally a petrol car with 1800cc has 1798cc in the book (I guess) so there's a greater chance a 1800cc car could avoid this tax bracket. And most probably the tax payment for the mentioned car must be over by now.