No. Mock allotment itself is not the real one. It gives you an indication of the allotment based on your choices. Anyway mock allotment is done over in JoSAA. First round is in.

Second point is slide and float are two terms that have to be understood correctly. See after an allotment is made, only the choices that are above the allotted one in your sheet will be considered for float. Float is when you wish to upgrade to a better seat than the one you have but that also will be the ones listed above the allotted one in your choice filling. So if you have been allotted the 10th choice in your list, you can only float for the 9 choices above because float is for the higher choices as entered by you. Slide is a seat within the same institute so for example you have been given a seat say in civil engg in IIT Guwahati, slide means you may stand a chance in other branches in IIT Guwahati only if vacancies arise.

Therefore the float and slide options are never given in any mock rounds simply because they are applicable only after an allotment is announced. Your choice filling is the one stage that should take care of all these things. Mock is to be used to reshuffle the choices for the actual round if needed.