Is we capable of applying l type visa for second time in the period of 6 months?

Yes, you can apply for the L type again. Apart from your passport, filled application form and a recent photo as same as the one used for your passport, you should provide the round-trip air tickets and hotel reservation in mainland China if you can provide the invitation letter. Also a letter of your personal details (where you go, who invites you and their name, address and contact information), a guarantee letter from your employer (name of your company, contact information and your salary) or a recent six months bank saving certificate is required.