Hey bro , only 12th Enough, 11th is not matter

For MBBS you shall require NEETUG for top colleges however you shall need PCB scores both in 11th and 12th to be eligible for NEET UG. 

Incase you dont have PCb in 11th you can take up state level entrance exams ljke COMEDK, MHTCET, etc from which you can apply to state level colleges both private and Government for MBBS courses.