Can I be eligible for applying to iiser aptitude test in this year ,presently I am studying in std 12th?

yes you can

There are three channels of admission. Candidates will be admitted to IISER only through these channels.

1. Kishore Vaigyanik Protsahan Yojana ( KVPY ) channel

2. Joint Entrance Examination of Indian Institutes of Technology ( JEE ) channel

3. State and Central Boards Channel ( SCB ) channel

These channels will be referred to as KVPY, JEE and SCB respectively

Indian nationals, and students belonging to PIO or OCI category are eligible to apply provided they satisfy the eligibility criteria described below.

KVPY Channel

Candidates having a valid KVPY fellowship commencing from 2018-19 academic session are eligible to apply for admissions. Additional cut-off criteria may be applicable.

JEE Channel

Candidates in General category securing a rank within 10000 in the Common Rank List (CRL) of JEE Advanced 2018 are eligible to apply. For candidates belonging to reserved category (OBCNC, SC, ST, PD), their category rank should be within 10000.

SCB Channel

Students who have passed (10+2) level with science stream in 2017 or 2018 with marks equal or above the cut off percentage in their respective boards as given in the table below are eligible to apply. For the candidates belonging to the Non-Creamy Layer of the Other Backward Classes (OBCNC) and Persons with Disability (PD) categories, there is a 5% relaxation. The cut-off percentage for the Scheduled Castes (SC), the Scheduled Tribes (ST) and Kashmiri Migrants (KM) candidates is 55% in (10+2) level for all boards.

Students applying through SCB channel will have to appear in the IISER Aptitude Test which will be conducted at various centres across the country. To calculate your percentage of marks obtained, use the percentage calculation method adopted by your board.