I am a bca completed student ,I want to do the MCA in sikkimmanippal university

Simultaneously with ur MCA get hands on with C on Linux, C++ on Linux, JAVA on Linux, PHP on Linux MySQL Database, Oracle Database as well. Cos Most of the Solutions now a days r Network Solutions and Linux is most popular in Network solutions. If u get certified with RHCE which will give u Linux Ad

Yes you can do it and either contact their office at Sikkim or their office at Manipal (Karnataka). You can even locate their study centre located near your place which help guide you throughout your MCA education.