I want to know who can use national emblem on his visiting cards ? can  an Army officer use it ?

Sir you please go through "The State emblem of India (prohibition of improper use Act, 2005) ". It says anyone who want to use the national emblem has to get permission from the competent authority before doing so.

printing of Indian flag is allowed in visiting card of a business man ?

http://mha.nic.in/pdfs/TheStateEmblemOfIndia(RegulationOfUse)Rules,2007.pdf

Rashi ji, The names and emblems (prevention of improper use) Act, 1950 in its Section 3 reads as :

3. Prohibition of improper use of certain emblems and names

Notwithstanding anything contained in any law for the time being in force, no person shall, except in such cases and under such conditions as may be prescribed by the Central Government use, or continue to use, for the purpose of any trade, business, calling or profession, or in the title of any patent, or in any trade mark or design, any name or emblem specified in the Schedule or, any colourable imitation thereof without the previous permission of the Central Government or of such officer of Government as may be authorised in this behalf by the Central Government.

So, a business man cannot use the national flag on his visiting card without Govt permission.

Thank you Vishal Sir and Suchitra mam.

thanks mr. Vishal for ur valuable information

Very Good topic and excellent discussion.  The information is very useful for all.  Congratulations plus thanks to all the participants.  This issue was come across when I was gone for registration of my organisation and I succeed with the reference as mentioned.

That is a nice thing to know Mr. Ram Samudre.  :)

Ms. Suchitra S., Thanks ! I'm really feeling appreciated.

KNOWLEDGE IS POWER.  The real friend is knowledge.  I believe that every coming movement, every coming second n every person coming across are carrying something new for me to learn and we can learn entire life till the last day. 

It is a great appreciation I feel from a Law Student who is not going to only earn from this profession but who also learnt the basic thoughts on our democratic constitution in depth... I appreciated that...  I'll never forget your participation of 23rd March in a task "Basic structure of Constitution"... Since than I become your fan BUT... ever keep this spirit up........ regards !!