Dear Tejas ,

MCA course you can take admission in two ways like Lateral entry and another way is regular in MCA full time course .where lateral entry is 2 year course duration and Full time course is 3 years duration .If you wants to admission MCA through lateral entry then you should must complete your graduation in  BCA course  else you can go through BSC for full time MCA course duration of 3 years .you cant take admission through lateral  entry after complete your Bsc course .

No , if you can go through lateral entry admission then you directly take admission in 2nd year of MCA course .There is no need to take exam in first year .

I hope it will helpful

Thanks