Dear Student ,

The best option for you from these two is PCMB. As you want to pursue Chemical Engineering , research , forensic and  radiations than you should definitely go for PCMB . For this you have to prepare for JEE Mains and JEE Advance . These are engineering entrance exams held after 12th class .

• By JEE Mains , you are able to get admission in various institutes like NIT's , IIIT's , GFTI's etc . You can take chemical engineering branch there and do your research .
• By JEE Advance , you are able to get admission in IIT's . There you can also take chemical engineering , forensic branch to do your research work .

Alos getting admission to these prestigious institutes will also provide you an environment , where you can explore research field . You will get full support from highly qualified professors . So along with PCMB you should prepare for these exams . Three subjects came in test of JEE Mains and Advance that are Physics , Chemistry and Maths . So go to NIT's , IIT's and do your favourite work .

Hope it helps.