By definition marriage is a social and legal contract.
I'm not sure what Hindi TV serials are showing these days, but there are some contractual stipulations that have emerged in marriages in the recent years. Some are legally recognized and some are not.
One kind is the visa/immigration marriage agreement. In this agreement people agree to get legally married for a limited duration so that one of them can get some visa/immigration benefits out of it. Similar agreements exist for other legal benefits of marriage. These are actually prohibited by law and if you are found marrying for these reasons you can criminal charges.
The limited term marriage is something that is covered in a pre-nuptial agreement. Usually a pre-nuptial agreement is a contract signed before marriage that spells out terms of divorce, alimony, child support, custody, joint property etc lest there be separation or divorce. Some pre-nuptials stipulate a time period after which either one can back out and get a divorce. Usually, you can't back out before the stipulated term either unless there is a special circumstance like cheating, fraud, abuse etc. The time stipulations are used by a lot of people who want to marry but feel hesitant, afraid, insecure etc. Since live-ins maybe frowned by some cultures, some people use time stipulated marriages as a go between living in and marriage.
Some people also spell out other reasons for divorce also in a pre-nuptial. There are rumors of people having absurd clauses that they will divorce if a spouse does not walk their dog twice a day or their weight increases to over 150 lbs or something.
Yes, one can engage in physical relations in the marriage. In fact the marriage is not complete unless it is consummated. Also if a marriage has not been consummated it can be annulled instead of divorce. Usually, people in time stipulated marriages agree not to have children within the period. Although, some contracts will spell out things like custody and child support in case of having a child in the period.
I'm not against pre-nuptials. It can be a good safety net, God forbid things go really wrong. But other than that a lot of these stipulations, conveniences etc don't make sense to me. It strips marriages of love, trust and commitment and makes them hollow and meaningless like business contracts. But if that is what people want, it is their choice. As long as they don't hurt or abuse each other or negatively effect their children.
82