Hello dear..

There is no such exams from where you can get directly get into research field after 12th because you need some core knowledge of that field before pursuing research work.But yes you get good results in 12th and can apply for iiser ,kvpy,iisc also you can complete your graduation from iits where you get fair chance to show your intrests in the research ; it will be easy.

Other than this also completing graduation will provide you opportunity to make your carrer in research field by applying for Csir net , Junior research fellow,Tifr graduate entrance test,Icmr junior research fellowship,Barc ,DBT Junior research fellowship in biotechnology etc.