Hello... I think that this is similar as for other standards. As i understood you are going to pack products that are produced under the HALAL, but you do not want to certify your company by HALAL.
TRADE DESCRIPTION ACT, 1972 In exercise of the powers conferred by section II of the Trade Descriptions Act, 1972, the Minister hereby makes the following order: 1. This Order may be cited as the Trade Descriptions (Marking of Food) Order, 1975. I. All food specified in the Schedule hereto which is Halal according to the Trade Description (Use of Expression Halal) Order, 1975 shall not be supplied unless it is marked by a label, tag or any other form of mark that such food is Halal...
But at the end if you want to mark HALAL on label, you must certify it on site of production. And additionally final product is the one packed at your site so you must confirm that you are operating on each line under the demands of HALAL.
I hope i helped