can i give iit without going to coaching classes but only by prepearing hsc mhtcet . if yes ,but my friends say no

Yes, you can appear for the IITJEE by self study also. But just by preparing for MHT-CET, you will not be able to clear IITJEE. You should have very good understanding of the subject PCM as the question asked in IITJEE is very tough compared to MHT-CET. But if you start self study and put hard work

Its depends on your ability and your dedication to study, i mean if you have guts to prepare at home than there is no problem but if you have doubt than join coaching.