You can offer discount coupon codes to your customers which apply a discount on the shipping rates. Your discount could be a percentage of the shipping fees, or a straight monetary reduction on the total shipping cost.
25% off shipping, or
Rs. 50/- off shipping fees
To learn how to create a discount coupon, read this article on Creating Discount Coupons.
NOTE: when you are creating the coupon, select "Shipping" in the relevant pulldown field, to apply the discount to the shipping fees.