I have not learnt any martial arts. However, I believe if I were to attain a state of inner discipline and peace I need to learn the arts. Unfortunately, I work in India and my earnings do not allow me to save handsomely. Can I approach a Shaolin temple in China or Japan and request a sensei to teach me in return for my services as a helper, teacher, worker at the temple? If so would you'll know any temples? Thank you for your time.
You can approach a Shaolin School, but it is highly unlikely that they will teach you in exchange for services.
The Shaolin Temple in China is essentially a business. They make a large profit from the money they get from students and have plenty of them. Smaller Shaolin Schools are also businesses.
You also mention temples in Japan. I assume by this you mean the Shorinji Kempo movement (of which I am a member) This is not actually shaolin kung fu but shares a similar zen philosophy. This is a multi-part organisation, but may as well be considered a business. The only way to get 'free' training that I know of with this organisation is the Busen School. These are basically monks (as opposed to people like me who you might call lay members) and I don't know how you would apply. You would certainly need to know Japanese first as this is the philosophical school and lessons are only taught in this language.
However it would be a mistake to think you have to go to china or japan to study martial arts. There are schools in India of the Shorinji Kempo Movement and I am certain of the actual Shaolin Kungfu as well.
Adding to Huw's answer (that these major temples are a lot like businesses now and probably will not accept alternatives for payment in exchange for teachings, though there may be some exceptions for those in monkhood) - it is worth noting that many schools, at least around the U.S. and with Chinese and Japanese martial arts, will offer flexible rates depending on income level. Based on the experiences of myself and my peers, you're more likely to have success forming that agreement if you can reach out to the leader to discuss it privately. If you are short on finances but can help support the school in other ways, maybe you can work out a deal like that (help setup and clean up, perform some other chores). If you have little income for now but are working to improve your situation, you might be able to get a discounted rate (e.g. a student discount).
The important thing there ties into Huw's bottom line as well: you don't need to go to physically travel far and abandon your house and job to get good martial art training which will help you cultivate a state of inner discipline and peace. Act locally, be sincere and honest, and be willing to emotionally travel and sacrifice. Not all schools will be flexible but I bet the more local the school, the better your chances, to be honest. For the school it can pay to be flexible with those in the community it is in, whereas they may want to avoid attracting unwanted attention by being flexible with travelers with little from far away.
According to my Sifu, the kung fu performed by Shaolin monks in the modern day is largely flashy wu-shu stuff. While it looks really cool for the tourists, it has little to no actual combat application. Don't go looking over seas, look for a school close to home that teaches real kung fu. Heung Gar, white eyebrow, chow gar, ship pal ki, wing chun and countless other styles are all taught in North America.
No, it's financially motivated now. History of Kung Fu post 19th century is a sad one. Due in large part to reforms made during and after the Cultural Revolution in China. During this period militant efforts to purge "traditional Chinese" culture to reinforce Maoism, led to the destruction of a lot of martial arts manuals, documents, and treatises as well as the extermination of many practitioners. Three million people were subject to be killed specifically because they were well known teachers of traditional Chinese culture, and this included well known martial artist. That's not mentioning the anti-Buddhist purges that targeted many Buddhists (and martial practitioners).
By the 60s and 70s, interest in martial arts from movies made in Hong Kong by Ip Man and Bruce Lee rekindled interest in kung fu/Wushu practices. Martial artists who escaped China went to Hong Kong, Japan, the US and Taiwan where they did their best to rebuild the schools of instructions with what little reference material they had available. In the 80s, kung fu movies took off successfully in the US home video market. And new actors Jet Li and Jackie Chan also help rekindle greater interest in westerners wanting to learn kung fu/wushu as a practice. VHS tapes of martial arts became amateur practice references, LONG before Billy Blanks and Tae Bo in the 90's.
The Chinese government used martial arts as a tourist draw, to market their teaching styles, and prospective students are being lured away by the draw of mixed martial arts (MMA), a combat sport that is exploding in popularity and requires no standard technique to implement. As a result, few fighters think of kung fu as a legitimate martial art any longer. Today, kung fu is a blend of martial technique and various isometric exercise, stretching, and elaborate gymnastics. You can learn martial arts at a temple, but be prepared to pony up the cash. You can learn outside China, if people are still around to teach.